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@@ -0,0 +1,6190 @@ +News for the tz database + +Release 2024a - 2024-02-01 09:28:56 -0800 + + Briefly: + Kazakhstan unifies on UTC+5 beginning 2024-03-01. + Palestine springs forward a week later after Ramadan. + zic no longer pretends to support indefinite-past DST. + localtime no longer mishandles Ciudad Juárez in 2422. + + Changes to future timestamps + + Kazakhstan unifies on UTC+5. This affects Asia/Almaty and + Asia/Qostanay which together represent the eastern portion of the + country that will transition from UTC+6 on 2024-03-01 at 00:00 to + join the western portion. (Thanks to Zhanbolat Raimbekov.) + + Palestine springs forward a week later than previously predicted + in 2024 and 2025. (Thanks to Heba Hamad.) Change spring-forward + predictions to the second Saturday after Ramadan, not the first; + this also affects other predictions starting in 2039. + + Changes to past timestamps + + Asia/Ho_Chi_Minh's 1955-07-01 transition occurred at 01:00 + not 00:00. (Thanks to Đoàn Trần Công Danh.) + + From 1947 through 1949, Toronto's transitions occurred at 02:00 + not 00:00. (Thanks to Chris Walton.) + + In 1911 Miquelon adopted standard time on June 15, not May 15. + + Changes to code + + The FROM and TO columns of Rule lines can no longer be "minimum" + or an abbreviation of "minimum", because TZif files do not support + DST rules that extend into the indefinite past - although these + rules were supported when TZif files had only 32-bit data, this + stopped working when 64-bit TZif files were introduced in 1995. + This should not be a problem for realistic data, since DST was + first used in the 20th century. As a transition aid, FROM columns + like "minimum" are now diagnosed and then treated as if they were + the year 1900; this should suffice for TZif files on old systems + with only 32-bit time_t, and it is more compatible with bugs in + 2023c-and-earlier localtime.c. (Problem reported by Yoshito + Umaoka.) + + localtime and related functions no longer mishandle some + timestamps that occur about 400 years after a switch to a time + zone with a DST schedule. In 2023d data this problem was visible + for some timestamps in November 2422, November 2822, etc. in + America/Ciudad_Juarez. (Problem reported by Gilmore Davidson.) + + strftime %s now uses tm_gmtoff if available. (Problem and draft + patch reported by Dag-Erling Smørgrav.) + + Changes to build procedure + + The leap-seconds.list file is now copied from the IERS instead of + from its downstream counterpart at NIST, as the IERS version is + now in the public domain too and tends to be more up-to-date. + (Thanks to Martin Burnicki for liaisoning with the IERS.) + + Changes to documentation + + The strftime man page documents which struct tm members affect + which conversion specs, and that tzset is called. (Problems + reported by Robert Elz and Steve Summit.) + + +Release 2023d - 2023-12-21 20:02:24 -0800 + + Briefly: + Ittoqqortoormiit, Greenland changes time zones on 2024-03-31. + Vostok, Antarctica changed time zones on 2023-12-18. + Casey, Antarctica changed time zones five times since 2020. + Code and data fixes for Palestine timestamps starting in 2072. + A new data file zonenow.tab for timestamps starting now. + + Changes to future timestamps + + Ittoqqortoormiit, Greenland (America/Scoresbysund) joins most of + the rest of Greenland's timekeeping practice on 2024-03-31, by + changing its time zone from -01/+00 to -02/-01 at the same moment + as the spring-forward transition. Its clocks will therefore not + spring forward as previously scheduled. The time zone change + reverts to its common practice before 1981. + + Fix predictions for DST transitions in Palestine in 2072-2075, + correcting a typo introduced in 2023a. + + Changes to past and future timestamps + + Vostok, Antarctica changed to +05 on 2023-12-18. It had been at + +07 (not +06) for years. (Thanks to Zakhary V. Akulov.) + + Change data for Casey, Antarctica to agree with timeanddate.com, + by adding five time zone changes since 2020. Casey is now at +08 + instead of +11. + + Changes to past tm_isdst flags + + Much of Greenland, represented by America/Nuuk, changed its + standard time from -03 to -02 on 2023-03-25, not on 2023-10-28. + This does not affect UTC offsets, only the tm_isdst flag. + (Thanks to Thomas M. Steenholdt.) + + New data file + + A new data file zonenow.tab helps configure applications that use + timestamps dated from now on. This simplifies configuration, + since users choose from a smaller Zone set. The file's format is + experimental and subject to change. + + Changes to code + + localtime.c no longer mishandles TZif files that contain a single + transition into a DST regime. Previously, it incorrectly assumed + DST was in effect before the transition too. (Thanks to Alois + Treindl for debugging help.) + + localtime.c's timeoff no longer collides with OpenBSD 7.4. + + The C code now uses _Generic only if __STDC_VERSION__ says the + compiler is C11 or later. + + tzselect now optionally reads zonenow.tab, to simplify when + configuring only for timestamps dated from now on. + + tzselect no longer creates temporary files. + + tzselect no longer mishandles the following: + + Spaces and most other special characters in BUGEMAIL, PACKAGE, + TZDIR, and VERSION. + + TZ strings when using mawk 1.4.3, which mishandles regular + expressions of the form /X{2,}/. + + ISO 6709 coordinates when using an awk that lacks the GNU + extension of newlines in -v option-arguments. + + Non UTF-8 locales when using an iconv command that lacks the GNU + //TRANSLIT extension. + + zic no longer mishandles data for Palestine after the year 2075. + Previously, it incorrectly omitted post-2075 transitions that are + predicted for just before and just after Ramadan. (Thanks to Ken + Murchison for debugging help.) + + zic now works again on Linux 2.6.16 and 2.6.17 (2006). + (Problem reported by Rune Torgersen.) + + Changes to build procedure + + The Makefile is now more compatible with POSIX: + * It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL. + * It no longer uses its own 'cc' in place of CC. + * It now uses ARFLAGS, with default specified by POSIX. + * It does not use LFLAGS incompatibly with POSIX. + * It uses the special .POSIX target. + * It quotes special characters more carefully. + * It no longer mishandles builds in an ISO 8859 locale. + Due to the CC changes, TZDIR is now #defined in a file tzfile.h + built by 'make', not in a $(CC) -D option. Also, TZDEFAULT is + now treated like TZDIR as they have similar roles. + + Changes to commentary + + Limitations and hazards of the optional support for obsolescent + C89 platforms are documented better, along with a tentative + schedule for removing this support. + + +Release 2023c - 2023-03-28 12:42:14 -0700 + + Changes to past and future timestamps + + Model Lebanon's DST chaos by reverting data to tzdb 2023a. + (Thanks to Rany Hany for the heads-up.) + + +Release 2023b - 2023-03-23 19:50:38 -0700 + + Changes to future timestamps + + This year Lebanon springs forward April 20/21 not March 25/26. + (Thanks to Saadallah Itani.) [This was reverted in 2023c.] + + +Release 2023a - 2023-03-22 12:39:33 -0700 + + Briefly: + Egypt now uses DST again, from April through October. + This year Morocco springs forward April 23, not April 30. + Palestine delays the start of DST this year. + Much of Greenland still uses DST from 2024 on. + America/Yellowknife now links to America/Edmonton. + tzselect can now use current time to help infer timezone. + The code now defaults to C99 or later. + Fix use of C23 attributes. + + Changes to future timestamps + + Starting in 2023, Egypt will observe DST from April's last Friday + through October's last Thursday. (Thanks to Ahmad ElDardiry.) + Assume the transition times are 00:00 and 24:00, respectively. + + In 2023 Morocco's spring-forward transition after Ramadan + will occur April 23, not April 30. (Thanks to Milamber.) + Adjust predictions for future years accordingly. This affects + predictions for 2023, 2031, 2038, and later years. + + This year Palestine will delay its spring forward from + March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.) + Make guesses for future Ramadans too. + + Much of Greenland, represented by America/Nuuk, will continue to + observe DST using European Union rules. When combined with + Greenland's decision not to change the clocks in fall 2023, + America/Nuuk therefore changes from -03/-02 to -02/-01 effective + 2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.) + This change from 2022g doesn't affect timestamps until 2024-03-30, + and doesn't affect tm_isdst until 2023-03-25. + + Changes to past timestamps + + America/Yellowknife has changed from a Zone to a backward + compatibility Link, as it no longer differs from America/Edmonton + since 1970. (Thanks to Almaz Mingaleev.) This affects some + pre-1948 timestamps. The old data are now in 'backzone'. + + Changes to past time zone abbreviations + + When observing Moscow time, Europe/Kirov and Europe/Volgograd now + use the abbreviations MSK/MSD instead of numeric abbreviations, + for consistency with other timezones observing Moscow time. + + Changes to code + + You can now tell tzselect local time, to simplify later choices. + Select the 'time' option in its first prompt. + + You can now compile with -DTZNAME_MAXIMUM=N to limit time zone + abbreviations to N bytes (default 255). The reference runtime + library now rejects POSIX-style TZ strings that contain longer + abbreviations, treating them as UTC. Previously the limit was + platform dependent and abbreviations were silently truncated to + 16 bytes even when the limit was greater than 16. + + The code by default is now designed for C99 or later. To build on + a mostly-C89 platform, compile with -DPORT_TO_C89; this should + work on C89 platforms that also support C99 'long long' and + perhaps a few other extensions to C89. To support C89 callers of + tzcode's library, compile with -DSUPPORT_C89; however, this could + trigger latent bugs in C99-or-later callers. The two new macros + are transitional aids planned to be removed in a future version + (say, in 2029), when C99 or later will be required. + + The code now builds again on pre-C99 platforms, if you compile + with -DPORT_TO_C89. This fixes a bug introduced in 2022f. + + On C23-compatible platforms tzcode no longer uses syntax like + 'static [[noreturn]] void usage(void);'. Instead, it uses + '[[noreturn]] static void usage(void);' as strict C23 requires. + (Problem reported by Houge Langley.) + + The code's functions now constrain their arguments with the C + 'restrict' keyword consistently with their documentation. + This may allow future optimizations. + + zdump again builds standalone with ckdadd and without setenv, + fixing a bug introduced in 2022g. (Problem reported by panic.) + + leapseconds.awk can now process a leap seconds file that never + expires; this might be useful if leap seconds are discontinued. + + Changes to commentary + + tz-link.html has a new section "Coordinating with governments and + distributors". (Thanks to Neil Fuller for some of the text.) + + To improve tzselect diagnostics, zone1970.tab's comments column is + now limited to countries that have multiple timezones. + + Note that leap seconds are planned to be discontinued by 2035. + + +Release 2022g - 2022-11-29 08:58:31 -0800 + + Briefly: + The northern edge of Chihuahua changes to US timekeeping. + Much of Greenland stops changing clocks after March 2023. + Fix some pre-1996 timestamps in northern Canada. + C89 is now deprecated; please use C99 or later. + Portability fixes for AIX, libintl, MS-Windows, musl, z/OS + In C code, use more C23 features if available. + C23 timegm now supported by default + Fixes for unlikely integer overflows + + Changes to future timestamps + + In the Mexican state of Chihuahua, the border strip near the US + will change to agree with nearby US locations on 2022-11-30. + The strip's western part, represented by Ciudad Juárez, switches + from -06 all year to -07/-06 with US DST rules, like El Paso, TX. + The eastern part, represented by Ojinaga, will observe US DST next + year, like Presidio, TX. (Thanks to Heitor David Pinto.) + A new Zone America/Ciudad_Juarez splits from America/Ojinaga. + + Much of Greenland, represented by America/Nuuk, stops observing + winter time after March 2023, so its daylight saving time becomes + standard time. (Thanks to Jonas Nyrup and Jürgen Appel.) + + Changes to past timestamps + + Changes for pre-1996 northern Canada (thanks to Chris Walton): + + Merge America/Iqaluit and America/Pangnirtung into the former, + with a backward compatibility link for the latter name. + There is no good evidence the two locations differ since 1970. + This change affects pre-1996 America/Pangnirtung timestamps. + + Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and + Yellowknife did not observe DST in 1965, and did observe DST + from 1972 through 1979. + + Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28. + + Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00. + (Thanks to Alois Treindl.) + + Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time), + not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.) + + Changes to code + + Although tzcode still works with C89, bugs found in recent routine + maintenance indicate that bitrot has set in and that in practice + C89 is no longer used to build tzcode. As it is a maintenance + burden, support for C89 is planned to be removed soon. Instead, + please use compilers compatible with C99, C11, C17, or C23. + + timegm, which tzcode implemented in 1989, will finally be + standardized 34 years later as part of C23, so timegm is now + supported even if STD_INSPIRED is not defined. + + Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone. + (Problem reported by Đoàn Trần Công Danh.) + + Fix bug in zic on hosts where malloc(0) yields NULL on success. + (Problem reported by Tim McBrayer for AIX 6.1.) + + Fix zic configuration to avoid linkage failures on some platforms. + (Problems reported by Gilmore Davidson and Igor Ivanov.) + + Work around MS-Windows nmake incompatibility with POSIX. + (Problem reported by Manuela Friedrich.) + + Port mktime and strftime to debugging platforms where accessing + uninitialized data has undefined behavior (strftime problem + reported by Robert Elz). + + Check more carefully for unlikely integer overflows, preferring + C23 <stdckdint.h> to overflow checking by hand, as the latter has + had obscure bugs. + + Changes to build procedure + + New Makefile rule check_mild that skips checking whether Link + lines are in the file 'backward'. (Inspired by a suggestion from + Stephen Colebourne.) + + +Release 2022f - 2022-10-28 18:04:57 -0700 + + Briefly: + Mexico will no longer observe DST except near the US border. + Chihuahua moves to year-round -06 on 2022-10-30. + Fiji no longer observes DST. + Move links to 'backward'. + In vanguard form, GMT is now a Zone and Etc/GMT a link. + zic now supports links to links, and vanguard form uses this. + Simplify four Ontario zones. + Fix a Y2438 bug when reading TZif data. + Enable 64-bit time_t on 32-bit glibc platforms. + Omit large-file support when no longer needed. + In C code, use some C23 features if available. + Remove no-longer-needed workaround for Qt bug 53071. + + Changes to future timestamps + + Mexico will no longer observe DST after 2022, except for areas + near the US border that continue to observe US DST rules. + On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves + from -07 (-06 with DST) to year-round -06, thus not changing + its clocks that day. The new law states that Chihuahua + near the US border no longer observes US DST. + (Thanks to gera for the heads-up about Chihuahua.) + + Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.) + For now, assume DST is suspended indefinitely. + + Changes to data + + Move links to 'backward' to ease and simplify link maintenance. + This affects generated data only if you use 'make BACKWARD='. + + GMT is now a Zone and Etc/GMT a link instead of vice versa, + as GMT is needed for leap second support whereas Etc/GMT is not. + However, this change exposes a bug in TZUpdater 2.3.2 so it is + present only in vanguard form for now. + + Vanguard form now uses links to links, as zic now supports this. + + Changes to past timestamps + + Simplify four Ontario zones, as most of the post-1970 differences + seem to have been imaginary. (Problem reported by Chris Walton.) + Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay + to 'backzone'; backward-compatibility links still work, albeit + with some different timestamps before November 2005. + + Changes to code + + zic now supports links to links regardless of input line order. + For example, if Australia/Sydney is a Zone, the lines + Link Australia/Canberra Australia/ACT + Link Australia/Sydney Australia/Canberra + now work correctly, even though the shell commands + ln Australia/Canberra Australia/ACT + ln Australia/Sydney Australia/Canberra + would fail because the first command attempts to use a link + Australia/Canberra that does not exist until after the second + command is executed. Previously, zic had unspecified behavior if + a Link line's target was another link, and zic often misbehaved if + a Link line's target was a later Link line. + + Fix line number in zic's diagnostic for a link to a link. + + Fix a bug that caused localtime to mishandle timestamps starting + in the year 2438 when reading data generated by 'zic -b fat' when + distant-future DST transitions occur at times given in standard + time or in UT, not the usual case of local time. This occurs when + the corresponding .zi Rule lines specify DST transitions with TO + columns of 'max' and AT columns that end in 's' or 'u'. The + number 2438 comes from the 32-bit limit in the year 2038, plus the + 400-year Gregorian cycle. (Problem reported by Bradley White.) + + On glibc 2.34 and later, which optionally supports 64-bit time_t + on platforms like x86 where time_t was traditionally 32 bits, + default time_t to 64 instead of 32 bits. This lets functions like + localtime support timestamps after the year 2038, and fixes + year-2038 problems in zic when accessing files dated after 2038. + To continue to limit time_t to 32 bits on these platforms, use + "make CFLAGS='-D_TIME_BITS=32'". + + In C code, do not enable large-file support on platforms like AIX + and macOS that no longer need it now that tzcode does not use + off_t or related functions like 'stat'. Large-file support is + still enabled by default on GNU/Linux, as it is needed for 64-bit + time_t support. + + In C code, prefer C23 keywords to pre-C23 macros for alignof, + bool, false, and true. Also, use the following C23 features if + available: __has_include, unreachable. + + zic no longer works around Qt bug 53071, as the relevant Qt + releases have been out of support since 2019. This change affects + only fat TZif files, as thin files never had the workaround. + + zdump no longer modifies the environ vector when compiled on + platforms lacking tm_zone or when compiled with -DUSE_LTZ=0. + This avoid undefined behavior on POSIX platforms. + + +Release 2022e - 2022-10-11 11:13:02 -0700 + + Briefly: + Jordan and Syria switch from +02/+03 with DST to year-round +03. + + Changes to future timestamps + + Jordan and Syria are abandoning the DST regime and are changing to + permanent +03, so they will not fall back from +03 to +02 on + 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.) + + Changes to past timestamps + + On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00. + + Changes to past time zone abbreviations and DST flags + + The temporary advancement of clocks in central Mexico in summer + 1931 is now treated as daylight saving time, instead of as two + changes to standard time. + + +Release 2022d - 2022-09-23 12:02:57 -0700 + + Briefly: + Palestine transitions are now Saturdays at 02:00. + Simplify three Ukraine zones into one. + + Changes to future timestamps + + Palestine now springs forward and falls back at 02:00 on the + first Saturday on or after March 24 and October 24, respectively. + This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00. + (Thanks to Heba Hamad.) + + Changes to past timestamps + + Simplify three Ukraine zones to one, since the post-1970 + differences seem to have been imaginary. Move Europe/Uzhgorod and + Europe/Zaporozhye to 'backzone'; backward-compatibility links + still work, albeit with different timestamps before October 1991. + + +Release 2022c - 2022-08-15 17:47:18 -0700 + + Briefly: + Work around awk bug in FreeBSD, macOS, etc. + Improve tzselect on intercontinental Zones. + + Changes to code + + Work around a bug in onetrueawk that broke commands like + 'make traditional_tarballs' on FreeBSD, macOS, etc. + (Problem reported by Deborah Goldsmith.) + + Add code to tzselect that uses experimental structured comments in + zone1970.tab to clarify whether Zones like Africa/Abidjan and + Europe/Istanbul cross continent or ocean boundaries. + (Inspired by a problem reported by Peter Krefting.) + + Fix bug with 'zic -d /a/b/c' when /a is unwritable but the + directory /a/b already exists. + + Remove zoneinfo2tdf.pl, as it was unused and triggered false + malware alarms on some email servers. + + +Release 2022b - 2022-08-10 15:38:32 -0700 + + Briefly: + Chile's DST is delayed by a week in September 2022. + Iran no longer observes DST after 2022. + Rename Europe/Kiev to Europe/Kyiv. + New zic -R option + Vanguard form now uses %z. + Finish moving duplicate-since-1970 zones to 'backzone'. + New build option PACKRATLIST + New tailored_tarballs target, replacing rearguard_tarballs + + Changes to future timestamps + + Chile's 2022 DST start is delayed from September 4 to September 11. + (Thanks to Juan Correa.) + + Iran plans to stop observing DST permanently, after it falls back + on 2022-09-21. (Thanks to Ali Mirjamali.) + + Changes to past timestamps + + Finish moving to 'backzone' the location-based zones whose + timestamps since 1970 are duplicates; adjust links accordingly. + This change ordinarily affects only pre-1970 timestamps, and with + the new PACKRATLIST option it does not affect any timestamps. + In this round the affected zones are Antarctica/Vostok, + Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik, + Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg, + Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas, + Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion, + Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei, + Pacific/Wake and Pacific/Wallis, and the affected links are + Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape, + Pacific/Truk, and Pacific/Yap. + + From fall 1994 through fall 1995, Shanks wrote that Crimea's + DST transitions were at 02:00 standard time, not at 00:00. + (Thanks to Michael Deckers.) + + Iran adopted standard time in 1935, not 1946. In 1977 it observed + DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on + 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979 + transition was on 05-27, not 03-21. + (Thanks to Roozbeh Pournader and Francis Santoni.) + + Chile's observance of -04 from 1946-08-29 through 1947-03-31 was + considered DST, not standard time. Santiago and environs had moved + their clocks back to rejoin the rest of mainland Chile; put this + change at the end of 1946-08-28. (Thanks to Michael Deckers.) + + Some old, small clock transitions have been removed, as people at + the time did not change their clocks. This affects Asia/Hong_Kong + in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880. + + Changes to zone name + + Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in + English now. Spelling of other names in Ukraine has not yet + demonstrably changed in common English practice so for now these + names retain old spellings, as in other countries (e.g., + Europe/Prague not "Praha", and Europe/Sofia not "Sofiya"). + + Changes to code + + zic has a new option '-R @N' to output explicit transitions < N. + (Need suggested by Almaz Mingaleev.) + + 'zic -r @N' no longer outputs bad data when N < first transition. + (Problem introduced in 2021d and reported by Peter Krefting.) + + zic now checks its input for NUL bytes and unterminated lines, and + now supports input line lengths up to 2048 (not 512) bytes. + + gmtime and related code now use the abbreviation "UTC" not "GMT". + POSIX is being revised to require this. + + When tzset and related functions set vestigial static variables + like tzname, they now prefer specified timestamps to unspecified ones. + (Problem reported by Almaz Mingaleev.) + + zic no longer complains "can't determine time zone abbreviation to + use just after until time" when a transition to a new standard + time occurs simultaneously with the first DST fallback transition. + + Changes to build procedure + + Source data in vanguard form now uses the %z notation, introduced + in release 2015f. For example, for America/Sao_Paulo vanguard + form contains the zone continuation line "-3:00 Brazil %z", which + is simpler and more reliable than the line "-3:00 Brazil -03/-02" + used in main and rearguard forms. The plan is for the main form + to use %z eventually; in the meantime maintainers of zi parsers + are encouraged to test the parsers on vanguard.zi. + + The Makefile has a new PACKRATLIST option to select a subset of + 'backzone'. For example, 'make PACKRATDATA=backzone + PACKRATLIST=zone.tab' now generates TZif files identical to those + of the global-tz project. + + The Makefile has a new tailored_tarballs target for generating + special-purpose tarballs. It generalizes and replaces the + rearguard_tarballs target and related targets and macros, which + are now obsolescent. + + 'make install' now defaults LOCALTIME to Factory not GMT, + which means the default abbreviation is now "-00" not "GMT". + + Remove the posix_packrat target, marked obsolescent in 2016a. + + +Release 2022a - 2022-03-15 23:02:01 -0700 + + Briefly: + Palestine will spring forward on 2022-03-27, not -03-26. + zdump -v now outputs better failure indications. + Bug fixes for code that reads corrupted TZif data. + + Changes to future timestamps + + Palestine will spring forward on 2022-03-27, not 2022-03-26. + (Thanks to Heba Hamad.) Predict future transitions for first + Sunday >= March 25. Additionally, predict fallbacks to be the first + Friday on or after October 23, not October's last Friday, to be more + consistent with recent practice. The first differing fallback + prediction is on 2025-10-24, not 2025-10-31. + + Changes to past timestamps + + From 1992 through spring 1996, Ukraine's DST transitions were at + 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.) + + Chile's Santiago Mean Time and its LMT precursor have been adjusted + eastward by 1 second to align with past and present law. + + Changes to commentary + + Add several references for Chile's 1946/1947 transitions, some of + which only affected portions of the country. + + Changes to code + + Fix bug when mktime gets confused by truncated TZif files with + unspecified local time. (Problem reported by Almaz Mingaleev.) + + Fix bug when 32-bit time_t code reads malformed 64-bit TZif data. + (Problem reported by Christos Zoulas.) + + When reading a version 2 or later TZif file, the TZif reader now + validates the version 1 header and data block only enough to skip + over them, as recommended by RFC 8536 section 4. Also, the TZif + reader no longer mistakenly attempts to parse a version 1 TZIf + file header as a TZ string. + + zdump -v now outputs "(localtime failed)" and "(gmtime failed)" + when local time and UT cannot be determined for a timestamp. + + Changes to build procedure + + Distribution tarballs now use standard POSIX.1-1988 ustar format + instead of GNU format. Although the formats are almost identical + for these tarballs, ustar headers' magic fields contain "ustar" + instead of "ustar ", and their version fields contain "00" instead + of " ". The two formats are planned to diverge more significantly + for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar + format becomes obsolete and the tarballs switch to pax format, an + extension of ustar. For details about these formats, please see + "pax - portable archive interchange", IEEE Std 1003.1-2017, + <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>. + + +Release 2021e - 2021-10-21 18:41:00 -0700 + + Changes to future timestamps + + Palestine will fall back 10-29 (not 10-30) at 01:00. + (Thanks to P Chan and Heba Hemad.) + + +Release 2021d - 2021-10-15 13:48:18 -0700 + + Briefly: + Fiji suspends DST for the 2021/2022 season. + 'zic -r' marks unspecified timestamps with "-00". + + Changes to future timestamps + + Fiji will suspend observance of DST for the 2021/2022 season. + Assume for now that it will return next year. (Thanks to Jashneel + Kumar and P Chan.) + + Changes to code + + 'zic -r' now uses "-00" time zone abbreviations for intervals + with UT offsets that are unspecified due to -r truncation. + This implements a change in draft Internet RFC 8536bis. + + +Release 2021c - 2021-10-01 14:21:49 -0700 + + Briefly: + Revert most 2021b changes to 'backward'. + Fix 'zic -b fat' bug in pre-1970 32-bit data. + Fix two Link line typos. + Distribute SECURITY file. + + This release is intended as a bugfix release, to fix compatibility + problems and typos reported since 2021b was released. + + Changes to Link directives + + Revert almost all of 2021b's changes to the 'backward' file, + by moving Link directives back to where they were in 2021a. + Although 'zic' doesn't care which source file contains a Link + directive, some downstream uses ran into trouble with the move. + (Problem reported by Stephen Colebourne for Joda-Time.) + + Fix typo that linked Atlantic/Jan_Mayen to the wrong location + (problem reported by Chris Walton). + + Fix 'backzone' typo that linked America/Virgin to the wrong + location (problem reported by Michael Deckers). + + Changes to code + + Fix a bug in 'zic -b fat' that caused old timestamps to be + mishandled in 32-bit-only readers (problem reported by Daniel + Fischer). + + Changes to documentation + + Distribute the SECURITY file (problem reported by Andreas Radke). + + +Release 2021b - 2021-09-24 16:23:00 -0700 + + Briefly: + Jordan now starts DST on February's last Thursday. + Samoa no longer observes DST. + Merge more location-based Zones whose timestamps agree since 1970. + Move some backward-compatibility links to 'backward'. + Rename Pacific/Enderbury to Pacific/Kanton. + Correct many pre-1993 transitions in Malawi, Portugal, etc. + zic now creates each output file or link atomically. + zic -L no longer omits the POSIX TZ string in its output. + zic fixes for truncation and leap second table expiration. + zic now follows POSIX for TZ strings using all-year DST. + Fix some localtime crashes and bugs in obscure cases. + zdump -v now outputs more-useful boundary cases. + tzfile.5 better matches a draft successor to RFC 8536. + A new file SECURITY. + + This release is prompted by recent announcements by Jordan and Samoa. + It incorporates many other changes that had accumulated since 2021a. + However, it omits most proposed changes that merged all Zones + agreeing since 1970, as concerns were raised about doing too many of + these changes at once. It does keeps some of these changes in the + interest of making tzdb more equitable one step at a time; see + "Merge more location-based Zones" below. + + Changes to future timestamps + + Jordan now starts DST on February's last Thursday. + (Thanks to Steffen Thorsen.) + + Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.) + + Changes to zone name + + Rename Pacific/Enderbury to Pacific/Kanton. When we added + Enderbury in 1993, we did not know that it is uninhabited and that + Kanton (population two dozen) is the only inhabited location in + that timezone. The old name is now a backward-compatibility link. + + Changes to past timestamps + + Correct many pre-1993 transitions, fixing entries originally + derived from Shanks, Whitman, and Mundell. The fixes include: + - Barbados: standard time was introduced in 1911, not 1932; and + DST was observed in 1942-1944 + - Cook Islands: In 1899 they switched from east to west of GMT, + celebrating Christmas for two days. They (and Niue) switched + to standard time in 1952, not 1901. + - Guyana: corrected LMT for Georgetown; the introduction of + standard time in 1911, not 1915; and corrections to 1975 and + 1992 transitions + - Kanton: uninhabited before 1937-08-31 + - Niue: only observed -11:20 from 1952 through 1964, then went to + -11 instead of -11:30 + - Portugal: DST was observed in 1950 + - Tonga: corrected LMT; the introduction of standard time in 1945, + not 1901; and corrections to the transition from +12:20 to +13 + in 1961, not 1941 + Additional fixes to entries in the 'backzone' file include: + - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09 + - The Gambia: 1933 and 1942 transitions + - Malawi: several 1911 through 1925 transitions + - Sierra Leone: several 1913 through 1941 transitions, and DST + was NOT observed in 1957 through 1962 + (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and + Alois Treindl.) + + Merge more location-based Zones whose timestamps agree since 1970, + as pre-1970 timestamps are out of scope. This is part of a + process that has been ongoing since 2013. This does not affect + post-1970 timestamps, and timezone historians who build with 'make + PACKRATDATA=backzone' should see no changes to pre-1970 timestamps. + When merging, keep the most-populous location's data, and move + data for other locations to 'backzone' with a backward + link in 'backward'. For example, move America/Creston data to + 'backzone' with a link in 'backward' from America/Phoenix because + the two timezones' timestamps agree since 1970; this change + affects some pre-1968 timestamps in America/Creston because + Creston and Phoenix disagreed before 1968. The affected Zones + are Africa/Accra, America/Atikokan, America/Blanc-Sablon, + America/Creston, America/Curacao, America/Nassau, + America/Port_of_Spain, Antarctica/DumontDUrville, and + Antarctica/Syowa. + + Changes to maintenance procedure + + The new file SECURITY covers how to report security-related bugs. + + Several backward-compatibility links have been moved to the + 'backward' file. These links, which range from Africa/Addis_Ababa + to Pacific/Saipan, are only for compatibility with now-obsolete + guidelines suggesting an entry for every ISO 3166 code. + The intercontinental convenience links Asia/Istanbul and + Europe/Nicosia have also been moved to 'backward'. + + Changes to code + + zic now creates each output file or link atomically, + possibly by creating a temporary file and then renaming it. + This avoids races where a TZ setting would temporarily stop + working while zic was installing a replacement file or link. + + zic -L no longer omits the POSIX TZ string in its output. + Starting with 2020a, zic -L truncated its output according to the + "Expires" directive or "#expires" comment in the leapseconds file. + The resulting TZif files omitted daylight saving transitions after + the leap second table expired, which led to far less accurate + predictions of times after the expiry. Although future timestamps + cannot be converted accurately in the presence of leap seconds, it + is more accurate to convert near-future timestamps with a few + seconds error than with an hour error, so zic -L no longer + truncates output in this way. + + Instead, when zic -L is given the "Expires" directive, it now + outputs the expiration by appending a no-change entry to the leap + second table. Although this should work well with most TZif + readers, it does not conform to Internet RFC 8536 and some pickier + clients (including tzdb 2017c through 2021a) reject it, so + "Expires" directives are currently disabled by default. To enable + them, set the EXPIRES_LINE Makefile variable. If a TZif file uses + this new feature it is marked with a new TZif version number 4, + a format intended to be documented in a successor to RFC 8536. + The old-format "#expires" comments are now treated solely as + comments and have no effect on the TZif files. + + zic -L LEAPFILE -r @LO no longer generates an invalid TZif file + that omits leap second information for the range LO..B when LO + falls between two leap seconds A and B. Instead, it generates a + TZif version 4 file that represents the previously missing + information. + + The TZif reader now allows the leap second table to begin with a + correction other than -1 or +1, and to contain adjacent + transitions with equal corrections. This supports TZif version 4. + + The TZif reader now lets leap seconds occur less than 28 days + apart. This supports possible future TZif extensions. + + Fix bug that caused 'localtime' etc. to crash when TZ was + set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does + not conform to POSIX but does conform to Internet RFC 8536. + + Fix another bug that caused 'localtime' etc. to crash when TZ was + set to a POSIX-conforming but unusual TZ string like + "EST5EDT4,0/0,J365/0", where almost all the year is DST. + + Fix yet another bug that caused 'localtime' etc. to mishandle slim + TZif files containing leap seconds after the last explicit + transition in the table, or when handling far-future timestamps + in slim TZif files lacking leap seconds. + + Fix localtime misbehavior involving positive leap seconds. + This change affects only behavior for "right" system time, + which contains leap seconds, and only if the UT offset is + not a multiple of 60 seconds when a positive leap second occurs. + (No such timezone exists in tzdb, luckily.) Without the fix, + the timestamp was ambiguous during a positive leap second. + With the fix, any seconds occurring after a positive leap second + and within the same localtime minute are counted through 60, not + through 59; their UT offset (tm_gmtoff) is the same as before. + Here is how the fix affects timestamps in a timezone with UT + offset +01:23:45 (5025 seconds) and with a positive leap second at + 1972-06-30 23:59:60 UTC (78796800): + + time_t without the fix with the fix + 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second) + 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46 + ... + 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60 + 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00 + + Fix an unlikely bug that caused 'localtime' etc. to misbehave if + civil time changes a few seconds before time_t wraps around, when + leap seconds are enabled. + + Fix bug in zic -r; in some cases, the dummy time type after the + last time transition disagreed with the TZ string, contrary to + Internet RFC 8563 section 3.3. + + Fix a bug with 'zic -r @X' when X is a negative leap second that + has a nonnegative correction. Without the fix, the output file + was truncated so that X appeared to be a positive leap second. + Fix a similar, even less likely bug when truncating at a positive + leap second that has a nonpositive correction. + + zic -r now reports an error if given rolling leap seconds, as this + usage has never generally worked and is evidently unused. + + zic now generates a POSIX-conforming TZ string for TZif files + where all-year DST is predicted for the indefinite future. + For example, for all-year Eastern Daylight Time, zic now generates + "XXX3EDT4,0/0,J365/23" where it previously generated + "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for + noting the possibility of POSIX conformance.) + + zic.c no longer requires sys/wait.h (thanks to spazmodius for + noting it wasn't needed). + + When reading slim TZif files, zdump no longer mishandles leap + seconds on the rare platforms where time_t counts leap seconds, + fixing a bug introduced in 2014g. + + zdump -v now outputs timestamps at boundaries of what localtime + and gmtime can represent, instead of the less useful timestamps + one day after the minimum and one day before the maximum. + (Thanks to Arthur David Olson for prototype code, and to Manuela + Friedrich for debugging help.) + + zdump's -c and -t options are now consistently inclusive for the + lower time bound and exclusive for the upper. Formerly they were + inconsistent. (Confusion noted by Martin Burnicki.) + + Changes to build procedure + + You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to + non-POSIX hosts where malloc doesn't set errno. + (Problem reported by Jan Engelhardt.) + + Changes to documentation + + tzfile.5 better matches a draft successor to RFC 8536 + <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>. + + +Release 2021a - 2021-01-24 10:54:57 -0800 + + Changes to future timestamps + + South Sudan changes from +03 to +02 on 2021-02-01 at 00:00. + (Thanks to Steffen Thorsen.) + + +Release 2020f - 2020-12-29 00:17:46 -0800 + + Change to build procedure + + 'make rearguard_tarballs' no longer generates a bad rearguard.zi, + fixing a 2020e bug. (Problem reported by Deborah Goldsmith.) + + +Release 2020e - 2020-12-22 15:14:34 -0800 + + Briefly: + Volgograd switches to Moscow time on 2020-12-27 at 02:00. + + Changes to future timestamps + + Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00. + (Thanks to Alexander Krivenyshev and Stepan Golosunov.) + + Changes to past timestamps + + Correct many pre-1986 transitions, fixing entries originally + derived from Shanks. The fixes include: + - Australia: several 1917 through 1971 transitions + - The Bahamas: several 1941 through 1945 transitions + - Bermuda: several 1917 through 1956 transitions + - Belize: several 1942 through 1968 transitions + - Ghana: several 1915 through 1956 transitions + - Israel and Palestine: several 1940 through 1985 transitions + - Kenya and adjacent: several 1908 through 1960 transitions + - Nigeria and adjacent: correcting LMT in Lagos, and several 1905 + through 1919 transitions + - Seychelles: the introduction of standard time in 1907, not 1906 + - Vanuatu: DST in 1973-1974, and a corrected 1984 transition + (Thanks to P Chan.) + + Because of the Australia change, Australia/Currie (King Island) is + no longer needed, as it is identical to Australia/Hobart for all + timestamps since 1970 and was therefore created by mistake. + Australia/Currie has been moved to the 'backward' file and its + corrected data moved to the 'backzone' file. + + Changes to past time zone abbreviations and DST flags + + To better match legislation in Turks and Caicos, the 2015 shift to + year-round observance of -04 is now modeled as AST throughout before + returning to Eastern Time with US DST in 2018, rather than as + maintaining EDT until 2015-11-01. (Thanks to P Chan.) + + Changes to documentation + + The zic man page now documents zic's coalescing of transitions + when a zone falls back just before DST springs forward. + + +Release 2020d - 2020-10-21 11:24:13 -0700 + + Briefly: + Palestine ends DST earlier than predicted, on 2020-10-24. + + Changes to past and future timestamps + + Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31 + as previously predicted (thanks to Sharef Mustafa.) Its + 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen + Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and + its spring 2020 transition was on March 28 at 00:00, not March 27 + (thanks to Pierre Cashon.) This affects Asia/Gaza and + Asia/Hebron. Assume future spring and fall transitions will be on + the Saturday preceding the last Sunday of March and October, + respectively. + + +Release 2020c - 2020-10-16 11:15:53 -0700 + + Briefly: + Fiji starts DST later than usual, on 2020-12-20. + + Changes to future timestamps + + Fiji will start DST on 2020-12-20, instead of 2020-11-08 as + previously predicted. DST will still end on 2021-01-17. + (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that + the later-than-usual start date is a one-time departure from the + recent pattern. + + Changes to build procedure + + Rearguard tarballs now contain an empty file pacificnew. + Some older downstream software expects this file to exist. + (Problem reported by Mike Cullinan.) + + +Release 2020b - 2020-10-06 18:35:04 -0700 + + Briefly: + Revised predictions for Morocco's changes starting in 2023. + Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08. + Macquarie Island has stayed in sync with Tasmania since 2011. + Casey, Antarctica is at +08 in winter and +11 in summer. + zic no longer supports -y, nor the TYPE field of Rules. + + Changes to future timestamps + + Morocco's spring-forward after Ramadan is now predicted to occur + no sooner than two days after Ramadan, instead of one day. + (Thanks to Milamber.) The first altered prediction is for 2023, + now predicted to spring-forward on April 30 instead of April 23. + + Changes to past and future timestamps + + Casey Station, Antarctica has been using +08 in winter and +11 in + summer since 2018. The most recent transition from +08 to +11 was + 2020-10-04 00:01. Also, Macquarie Island has been staying in + sync with Tasmania since 2011. (Thanks to Steffen Thorsen.) + + Changes to past and future time zone abbreviations and DST flags + + Canada's Yukon, represented by America/Whitehorse and + America/Dawson, changes its time zone rules from -08/-07 to + permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it. + This change affects only the time zone abbreviation (MST vs PDT) + and daylight saving flag for the period between the two dates. + (Thanks to Andrew G. Smith.) + + Changes to past timestamps + + Correct several transitions for Hungary for 1918/1983. + For example, the 1983-09-25 fall-back was at 01:00, not 03:00. + (Thanks to Géza Nyáry.) Also, the 1890 transition to standard + time was on 11-01, not 10-01 (thanks to Michael Deckers). + + The 1891 French transition was on March 16, not March 15. The + 1911-03-11 French transition was at midnight, not a minute later. + Monaco's transitions were on 1892-06-01 and 1911-03-29, not + 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.) + + Changes to code + + Support for zic's long-obsolete '-y YEARISTYPE' option has been + removed and, with it, so has support for the TYPE field in Rule + lines, which is now reserved for compatibility with earlier zic. + These features were previously deprecated in release 2015f. + (Thanks to Tim Parenti.) + + zic now defaults to '-b slim' instead of to '-b fat'. + + zic's new '-l -' and '-p -' options uninstall any existing + localtime and posixrules files, respectively. + + The undocumented and ineffective tzsetwall function has been + removed. + + Changes to build procedure + + The Makefile now defaults POSIXRULES to '-', so the posixrules + feature (obsolete as of 2019b) is no longer installed by default. + + Changes to documentation and commentary + + The long-obsolete files pacificnew, systemv, and yearistype.sh have + been removed from the distribution. (Thanks to Tim Parenti.) + + +Release 2020a - 2020-04-23 16:03:47 -0700 + + Briefly: + Morocco springs forward on 2020-05-31, not 2020-05-24. + Canada's Yukon advanced to -07 year-round on 2020-03-08. + America/Nuuk renamed from America/Godthab. + zic now supports expiration dates for leap second lists. + + Changes to future timestamps + + Morocco's second spring-forward transition in 2020 will be May 31, + not May 24 as predicted earlier. (Thanks to Semlali Naoufal.) + Adjust future-year predictions to use the first Sunday after the + day after Ramadan, not the first Sunday after Ramadan. + + Canada's Yukon, represented by America/Whitehorse and + America/Dawson, advanced to -07 year-round, beginning with its + spring-forward transition on 2020-03-08, and will not fall back on + 2020-11-01. Although a government press release calls this + "permanent Pacific Daylight Saving Time", we prefer MST for + consistency with nearby Dawson Creek, Creston, and Fort Nelson. + (Thanks to Tim Parenti.) + + Changes to past timestamps + + Shanghai observed DST in 1919. (Thanks to Phake Nick.) + + Changes to timezone identifiers + + To reflect current usage in English better, America/Godthab has + been renamed to America/Nuuk. A backwards-compatibility link + remains for the old name. + + Changes to code + + localtime.c no longer mishandles timestamps after the last + transition in a TZif file with leap seconds and with daylight + saving time transitions projected into the indefinite future. + For example, with TZ='America/Los_Angeles' with leap seconds, + zdump formerly reported a DST transition on 2038-03-14 + from 01:59:32.999... to 02:59:33 instead of the correct transition + from 01:59:59.999... to 03:00:00. + + zic -L now supports an Expires line in the leapseconds file, and + truncates the TZif output accordingly. This propagates leap + second expiration information into the TZif file, and avoids the + abovementioned localtime.c bug as well as similar bugs present in + many client implementations. If no Expires line is present, zic + -L instead truncates the TZif output based on the #expires comment + present in leapseconds files distributed by tzdb 2018f and later; + however, this usage is obsolescent. For now, the distributed + leapseconds file has an Expires line that is commented out, so + that the file can be fed to older versions of zic which ignore the + commented-out line. Future tzdb distributions are planned to + contain a leapseconds file with an Expires line. + + The configuration macros HAVE_TZNAME and USG_COMPAT should now be + set to 1 if the system library supports the feature, and 2 if not. + As before, these macros are nonzero if tzcode should support the + feature, zero otherwise. + + The configuration macro ALTZONE now has the same values with the + same meaning as HAVE_TZNAME and USG_COMPAT. + + The code's defense against CRLF in leap-seconds.list is now + portable to POSIX awk. (Problem reported by Deborah Goldsmith.) + + Although the undocumented tzsetwall function is not changed in + this release, it is now deprecated in preparation for removal in + future releases. Due to POSIX requirements, tzsetwall has not + worked for some time. Any code that uses it should instead use + tzalloc(NULL) or, if portability trumps thread-safety, should + unset the TZ environment variable. + + Changes to commentary + + The Îles-de-la-Madeleine and the Listuguj reserve are noted as + following America/Halifax, and comments about Yukon's "south" and + "north" have been corrected to say "east" and "west". (Thanks to + Jeffery Nichols.) + + +Release 2019c - 2019-09-11 08:59:48 -0700 + + Briefly: + Fiji observes DST from 2019-11-10 to 2020-01-12. + Norfolk Island starts observing Australian-style DST. + + Changes to future timestamps + + Fiji's next DST transitions will be 2019-11-10 and 2020-01-12 + instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.) + Adjust future guesses accordingly. + + Norfolk Island will observe Australian-style DST starting in + spring 2019. The first transition is on 2019-10-06. (Thanks to + Kyle Czech and Michael Deckers.) + + Changes to past timestamps + + Many corrections to time in Turkey from 1940 through 1985. + (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.) + + The Norfolk Island 1975-03-02 transition was at 02:00 standard + time, not 02:00 DST. (Thanks to Michael Deckers.) + + South Korea observed DST from 1948 through 1951. Although this + info was supposed to appear in release 2014j, a typo inadvertently + suppressed the change. (Thanks to Alois Treindl.) + + Detroit observed DST in 1967 and 1968 following the US DST rules, + except that its 1967 DST began on June 14 at 00:01. (Thanks to + Alois Treindl for pointing out that the old data entries were + probably wrong.) + + Fix several errors in pre-1970 transitions in Perry County, IN. + (Thanks to Alois Treindl for pointing out the 1967/9 errors.) + + Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver + ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not + 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02 + to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated + EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946 + Königsberg switched to +03 on 04-07 not 01-01. + + In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not + 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.) + Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27. + + The 1892-05-01 transition in Brussels was at 00:17:30, not at noon. + (Thanks to Michael Deckers.) + + Changes to past time zone abbreviations and DST flags + + Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25, + is now flagged as DST and is abbreviated HKWT not HKT. + + Changes to code + + leapseconds.awk now relies only on its input data, rather than + also relying on its comments. (Inspired by code from Dennis + Ferguson and Chris Woodbury.) + + The code now defends against CRLFs in leap-seconds.list. + (Thanks to Brian Inglis and Chris Woodbury.) + + Changes to documentation and commentary + + theory.html discusses leap seconds. (Thanks to Steve Summit.) + + Nashville's newspapers dueled about the time of day in the 1950s. + (Thanks to John Seigenthaler.) + + Liechtenstein observed Swiss DST in 1941/2. + (Thanks to Alois Treindl.) + + +Release 2019b - 2019-07-01 00:09:53 -0700 + + Briefly: + Brazil no longer observes DST. + 'zic -b slim' outputs smaller TZif files; please try it out. + Palestine's 2019 spring-forward transition was on 03-29, not 03-30. + + Changes to future timestamps + + Brazil has canceled DST and will stay on standard time indefinitely. + (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de + Oliveira.) + + Predictions for Morocco now go through 2087 instead of 2037, to + work around a problem on newlib when using TZif files output by + zic 2019a or earlier. (Problem reported by David Gauchard.) + + Changes to past and future timestamps + + Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30 + at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess + future transitions to be March's last Friday at 00:00. + + Changes to past timestamps + + Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not + 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00, + not 09-15 at 00:00. In 1946 its spring-forward transition was on + 04-21 at 00:00, not the previous day at 03:30. From 1946 through + 1952 its fall-back transitions occurred at 04:30, not at 03:30. + In 1947 its fall-back transition was on 11-30, not 12-30. + (Thanks to P Chan.) + + Changes to past time zone abbreviations + + Italy's 1866 transition to Rome Mean Time was on December 12, not + September 22. This affects only the time zone abbreviation for + Europe/Rome between those dates. (Thanks to Stephen Trainor and + Luigi Rosa.) + + Changes affecting metadata only + + Add info about the Crimea situation in zone1970.tab and zone.tab. + (Problem reported by Serhii Demediuk.) + + Changes to code + + zic's new -b option supports a way to control data bloat and to + test for year-2038 bugs in software that reads TZif files. + 'zic -b fat' and 'zic -b slim' generate larger and smaller output; + for example, changing from fat to slim shrinks the Europe/London + file from 3648 to 1599 bytes, saving about 56%. Fat and slim + files represent the same set of timestamps and use the same TZif + format as documented in tzfile(5) and in Internet RFC 8536. + Fat format attempts to work around bugs or incompatibilities in + older software, notably software that mishandles 64-bit TZif data + or uses obsolete TZ strings like "EET-2EEST" that lack DST rules. + Slim format is more efficient and does not work around 64-bit bugs + or obsolete TZ strings. Currently zic defaults to fat format + unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this + out-of-the-box default is intended to change in future releases + as the buggy software often mishandles timestamps anyway. + + zic no longer treats a set of rules ending in 2037 specially. + Previously, zic assumed that such a ruleset meant that future + timestamps could not be predicted, and therefore omitted a + POSIX-like TZ string in the TZif output. The old behavior is no + longer needed for current tzdata, and caused problems with newlib + when used with older tzdata (reported by David Gauchard). + + zic no longer generates some artifact transitions. For example, + Europe/London no longer has a no-op transition in January 1996. + + Changes to build procedure + + tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi + by a percent or so. + + Changes to documentation and commentary + + The Makefile now documents the POSIXRULES macro as being obsolete, + and similarly, zic's -p POSIXRULES option is now documented as + being obsolete. Although the POSIXRULES feature still exists and + works as before, in practice it is rarely used for its intended + purpose, and it does not work either in the default reference + implementation (for timestamps after 2037) or in common + implementations such as GNU/Linux (for contemporary timestamps). + Since POSIXRULES was designed primarily as a temporary transition + facility for System V platforms that died off decades ago, it is + being decommissioned rather than institutionalized. + + New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick). + + +Release 2019a - 2019-03-25 22:01:33 -0700 + + Briefly: + Palestine "springs forward" on 2019-03-30 instead of 2019-03-23. + Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00. + + Changes to past and future timestamps + + Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as + previously predicted. Adjust our prediction by guessing that spring + transitions will be between 24 and 30 March, which matches recent practice + since 2016. (Thanks to Even Scharning and Tim Parenti.) + + Metlakatla ended its observance of Pacific standard time, + rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan + Stanley and Tim Parenti.) + + Changes to past timestamps + + Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25). + (Thanks to Alois Treindl and Isaac Starkman.) + + Changes to time zone abbreviations + + Etc/UCT is now a backward-compatibility link to Etc/UTC, instead + of being a separate zone that generates the abbreviation "UCT", + which nowadays is typically a typo. (Problem reported by Isiah + Meadows.) + + Changes to code + + zic now has an -r option to limit the time range of output data. + For example, 'zic -r @1000000000' limits the output data to + timestamps starting 1000000000 seconds after the Epoch. + This helps shrink output size and can be useful for applications + not needing the full timestamp history, such as TZDIST truncation; + see Internet RFC 8536 section 5.1. (Inspired by a feature request + from Christopher Wong, helped along by bug reports from Wong and + from Tim Parenti.) + + Changes to documentation + + Mention Internet RFC 8536 (February 2019), which documents TZif. + + tz-link.html now cites tzdata-meta + <https://tzdata-meta.timtimeonline.com/>. + + +Release 2018i - 2018-12-30 11:05:43 -0800 + + Briefly: + São Tomé and Príncipe switches from +01 to +00 on 2019-01-01. + + Changes to future timestamps + + Due to a change in government, São Tomé and Príncipe switches back + from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim + Nasardinov and Michael Deckers.) + + +Release 2018h - 2018-12-23 17:59:32 -0800 + + Briefly: + Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21. + New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move. + Metlakatla, Alaska observes PST this winter only. + Guess Morocco will continue to adjust clocks around Ramadan. + Add predictions for Iran from 2038 through 2090. + + Changes to future timestamps + + Guess that Morocco will continue to fall back just before and + spring forward just after Ramadan, the practice since 2012. + (Thanks to Maamar Abdelkader.) This means Morocco will observe + negative DST during Ramadan in main and vanguard formats, and in + rearguard format it stays in the +00 timezone and observes + ordinary DST in all months other than Ramadan. As before, extend + this guesswork to the year 2037. As a consequence, Morocco is + scheduled to observe three DST transitions in some Gregorian years + (e.g., 2033) due to the mismatch between the Gregorian and Islamic + calendars. + + The table of exact transitions for Iranian DST has been extended. + It formerly cut off before the year 2038 in a nod to 32-bit time_t. + It now cuts off before 2091 as there is doubt about how the Persian + calendar will treat 2091. This change predicts DST transitions in + 2038-9, 2042-3, and 2046-7 to occur one day later than previously + predicted. As before, post-cutoff transitions are approximated. + + Changes to past and future timestamps + + Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to + +05 on 2018-12-21. This is a zone split as Qostanay (aka + Kostanay) did not switch, so create a zone Asia/Qostanay. + + Metlakatla moved from Alaska to Pacific standard time on 2018-11-04. + It did not change clocks that day and remains on -08 this winter. + (Thanks to Ryan Stanley.) It will revert to the usual Alaska + rules next spring, so this change affects only timestamps + from 2018-11-04 through 2019-03-10. + + Change to past timestamps + + Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00, + not 00:00. I transcribed the time incorrectly from Shanks. + (Thanks to Phake Nick.) + + Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00. + (Thanks to Phake Nick.) + + Guam observed DST irregularly from 1959 through 1977. + (Thanks to Phake Nick.) + + Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on + 10-01 changed standard time to +08:30 (not +08). Its transition + back to +08 after WWII was on 1945-09-15, not the previous day. + Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT). + (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also, + its 1952 fallback was on 11-02 (not 10-25). + + This release contains many changes to timestamps before 1946 due + to Japanese possession or occupation of Pacific/Chuuk, + Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro, + Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei. + (Thanks to Phake Nick.) + + Assume that the Spanish East Indies was like the Philippines and + observed American time until the end of 1844. This affects + Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei. + + Changes to past tm_isdst flags + + For the recent Morocco change, the tm_isdst flag should be 1 from + 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.) + Give a URL to the official decree. (Thanks to Matt Johnson.) + + +Release 2018g - 2018-10-26 22:22:45 -0700 + + Briefly: + Morocco switches to permanent +01 on 2018-10-28. + + Changes to future timestamps + + Morocco switches from +00/+01 to permanent +01 effective 2018-10-28, + so its clocks will not fall back as previously scheduled. + (Thanks to Mohamed Essedik Najd and Brian Inglis.) + + Changes to code + + When generating TZif files with leap seconds, zic no longer uses a + format that trips up older 32-bit clients, fixing a bug introduced + in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround + for QTBUG-53071 now also works for TZif files with leap seconds. + + The translator to rearguard format now rewrites the line + "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to + "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S". + This caters to zic before 2007 and to Oracle TZUpdater 2.2.0 + and earlier. (Reported by Christos Zoulas.) + + Changes to past time zone abbreviations + + Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii. + This reverts to 2011h, as the abbreviation change in 2011i was + likely inadvertent. + + Changes to documentation + + tzfile.5 has new sections on interoperability issues. + + +Release 2018f - 2018-10-18 00:14:18 -0700 + + Briefly: + Volgograd moves from +03 to +04 on 2018-10-28. + Fiji ends DST 2019-01-13, not 2019-01-20. + Most of Chile changes DST dates, effective 2019-04-06. + + Changes to future timestamps + + Volgograd moves from +03 to +04 on 2018-10-28 at 02:00. + (Thanks to Alexander Fetisov and Stepan Golosunov.) + + Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously + predicted. (Thanks to Raymond Kumar.) Adjust future predictions + accordingly. + + Most of Chile will end DST on the first Saturday in April at 24:00 mainland + time, and resume DST on the first Saturday in September at 24:00 mainland + time. The changes are effective from 2019-04-06, and do not affect the + Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa + and Tim Parenti.) Adjust future predictions accordingly. + + Changes to past timestamps + + The 2018-05-05 North Korea 30-minute time zone change took place + at 23:30 the previous day, not at 00:00 that day. + + China's 1988 spring-forward transition was on April 17, not + April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00. + (Thanks to P Chan.) + + Fix several issues for Macau before 1992. Macau's pre-1904 LMT + was off by 10 s. Macau switched to +08 in 1904 not 1912, and + temporarily switched to +09/+10 during World War II. Macau + observed DST in 1942/79, not 1961/80, and there were several + errors for transition times and dates. (Thanks to P Chan.) + + The 1948-1951 fallback transitions in Japan were at 25:00 on + September's second Saturday, not at 24:00. (Thanks to Phake Nick.) + zic turns this into 01:00 on the day after September's second + Saturday, which is the best that POSIX or C platforms can do. + + Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014 + paper by Li Yu, replacing more-questionable data from Shanks. + + Changes to time zone abbreviations + + Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.) + + Changes to code + + zic now always generates TZif files where time type 0 is used for + timestamps before the first transition. This simplifies the + reading of TZif files and should not affect behavior of existing + TZif readers because the same set of time types is used; only + their internal indexes may have changed. This affects only the + legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and + EET, which previously used nonzero types for these timestamps. + + Because of the type 0 change, zic no longer outputs a dummy + transition at time -2**59 (before the Big Bang), as clients should + no longer need this to handle historical timestamps correctly. + This reverts a change introduced in 2013d and shrinks most TZif + files by a few bytes. + + zic now supports negative time-of-day in Rule and Leap lines, e.g., + "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition + occurs at 18:00 on the Saturday before the last Sunday in April. + This behavior was documented in 2018a but the code did not + entirely match the documentation. + + localtime.c no longer requires at least one time type in TZif + files that lack transitions or have a POSIX-style TZ string. This + future-proofs the code against possible future extensions to the + format that would allow TZif files with POSIX-style TZ strings and + without transitions or time types. + + A read-access subscript error in localtime.c has been fixed. + It could occur only in TZif files with timecnt == 0, something that + does not happen in practice now but could happen in future versions. + + localtime.c no longer ignores TZif POSIX-style TZ strings that + specify only standard time. Instead, these TZ strings now + override the default time type for timestamps after the last + transition (or for all timestamps if there are no transitions), + just as DST strings specifying DST have always done. + + leapseconds.awk now outputs "#updated" and "#expires" comments, + and supports leap seconds at the ends of months other than June + and December. (Inspired by suggestions from Chris Woodbury.) + + Changes to documentation + + New restrictions: A Rule name must start with a character that + is neither an ASCII digit nor "-" nor "+", and an unquoted name + should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~". + The latter restriction makes room for future extensions (a + possibility noted by Tom Lane). + + tzfile.5 now documents what time types apply before the first and + after the last transition, if any. + + Documentation now uses the spelling "timezone" for a TZ setting + that determines timestamp history, and "time zone" for a + geographic region currently sharing the same standard time. + + The name "TZif" is now used for the tz binary data format. + + tz-link.htm now mentions the A0 TimeZone Migration utilities. + (Thanks to Aldrin Martoq for the link.) + + Changes to build procedure + + New 'make' target 'rearguard_tarballs' to build the rearguard + tarball only. This is a convenience on platforms that lack lzip + if you want to build the rearguard tarball. (Problem reported by + Deborah Goldsmith.) + + tzdata.zi is now more stable from release to release. (Problem + noted by Tom Lane.) It is also a bit shorter. + + tzdata.zi now can contain comment lines documenting configuration + information, such as which data format was selected, which input + files were used, and how leap seconds are treated. (Problems + noted by Lester Caine and Brian Inglis.) If the Makefile defaults + are used these comment lines are absent, for backward + compatibility. A redistributor intending to alter its copy of the + files should also append "-LABEL" to the 'version' file's first + line, where "LABEL" identifies the redistributor's change. + + +Release 2018e - 2018-05-01 23:42:51 -0700 + + Briefly: + + North Korea switches back to +09 on 2018-05-05. + The main format uses negative DST again, for Ireland etc. + 'make tarballs' now also builds a rearguard tarball. + New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines. + + Changes to past and future timestamps + + North Korea switches back from +0830 to +09 on 2018-05-05. + (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon, + and Tim Parenti.) + + Bring back the negative-DST changes of 2018a, except be more + compatible with data parsers that do not support negative DST. + Also, this now affects historical timestamps in Namibia and the + former Czechoslovakia, not just Ireland. The main format now uses + negative DST to model timestamps in Europe/Dublin (from 1971 on), + Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This + does not affect UT offsets, only time zone abbreviations and the + tm_isdst flag. Also, this does not affect rearguard or vanguard + formats; effectively the main format now uses vanguard instead of + rearguard format. Data parsers that do not support negative DST + can still use data from the rearguard tarball described below. + + Changes to build procedure + + The command 'make tarballs' now also builds the tarball + tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz + except that it uses rearguard format intended for trailing-edge + data parsers. + + Changes to data format and to code + + The SAVE column of Rule and Zone lines can now have an 's' or 'd' + suffix, which specifies whether the adjusted time is standard time + or daylight saving time. If no suffix is given, daylight saving + time is used if and only if the SAVE column is nonzero; this is + the longstanding behavior. Although this new feature is not used + in tzdata, it could be used to specify the legal time in Namibia + 1994-2017, as opposed to the popular time (see below). + + Changes to past timestamps + + From 1994 through 2017 Namibia observed DST in winter, not summer. + That is, it used negative DST, as Ireland still does. This change + does not affect UTC offsets; it affects only the tm_isdst flag and + the abbreviation used during summer, which is now CAT, not WAST. + Although (as noted by Michael Deckers) summer and winter time were + both simply called "standard time" in Namibian law, in common + practice winter time was considered to be DST (as noted by Stephen + Colebourne). The full effect of this change is only in vanguard + and main format; in rearguard format, the tm_isdst flag is still + zero in winter and nonzero in summer. + + In 1946/7 Czechoslovakia also observed negative DST in winter. + The full effect of this change is only in vanguard and main + formats; in rearguard format, it is modeled as plain GMT without + daylight saving. Also, the dates of some 1944/5 DST transitions + in Czechoslovakia have been changed. + + +Release 2018d - 2018-03-22 07:05:46 -0700 + + Briefly: + + Palestine starts DST a week earlier in 2018. + Add support for vanguard and rearguard data consumers. + Add subsecond precision to source data format, though not to data. + + Changes to future timestamps + + In 2018, Palestine starts DST on March 24, not March 31. + Adjust future predictions accordingly. (Thanks to Sharef Mustafa.) + + Changes to past and future timestamps + + Casey Station in Antarctica changed from +11 to +08 on 2018-03-11 + at 04:00. (Thanks to Steffen Thorsen.) + + Changes to past timestamps + + Historical transitions for Uruguay, represented by + America/Montevideo, have been updated per official legal documents, + replacing previous data mainly originating from the inventions of + Shanks & Pottenger. This has resulted in adjustments ranging from + 30 to 90 minutes in either direction over at least two dozen + distinct periods ranging from one day to several years in length. + A mere handful of pre-1991 transitions are unaffected; data since + then has come from more reliable contemporaneous reporting. These + changes affect various timestamps in 1920-1923, 1936, 1939, + 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990. + Additionally, Uruguay's pre-standard-time UT offset has been + adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to + match the location of the Observatory of the National Meteorological + Institute in Montevideo. + (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.) + + East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995. + (Thanks to Kerry Shetline.) + + Fix the 1912-01-01 transition for Portugal and its colonies. + This transition was at 00:00 according to the new UT offset, not + according to the old one. Also assume that Cape Verde switched on + the same date as the rest, not in 1907. This affects + Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores, + Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon. + (Thanks to Michael Deckers.) + + Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in + Turks & Caicos. + + Changes to past time zone abbreviations + + MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There + is no clock change associated with the transition. + + Changes to build procedure + + The new DATAFORM macro in the Makefile lets the installer choose + among three source data formats. The idea is to lessen downstream + disruption when data formats are improved. + + * DATAFORM=vanguard installs from the latest, bleeding-edge + format. DATAFORM=main (the default) installs from the format + used in the 'africa' etc. files. DATAFORM=rearguard installs + from a trailing-edge format. Eventually, elements of today's + vanguard format should move to the main format, and similarly + the main format's features should eventually move to the + rearguard format. + + * In the current version, the main and rearguard formats are + identical and match that of 2018c, so this change does not + affect default behavior. The vanguard format currently contains + one feature not in the main format: negative SAVE values. This + improves support for Ireland, which uses Irish Standard Time + (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has + supported negative SAVE values for decades, and this feature + should move to the main format soon. However, it will not move + to the rearguard format for quite some time because some + downstream parsers do not support it. + + * The build procedure constructs three files vanguard.zi, main.zi, + and rearguard.zi, one for each format. Although the files + represent essentially the same data, they may have minor + discrepancies that users are not likely to notice. The files + are intended for downstream data consumers and are not + installed. Zoneinfo parsers that do not support negative SAVE values + should start using rearguard.zi, so that they will be unaffected + when the negative-DST feature moves from vanguard to main. + Bleeding-edge Zoneinfo parsers that support the new features + already can use vanguard.zi; in this respect, current tzcode is + bleeding-edge. + + The Makefile should now be safe for parallelized builds, and 'make + -j to2050new.tzs' is now much faster on a multiprocessor host + with GNU Make. + + When built with -DSUPPRESS_TZDIR, the tzcode library no longer + prepends TZDIR/ to file names that do not begin with '/'. This is + not recommended for general use, due to its security implications. + (From a suggestion by Manuela Friedrich.) + + Changes to code + + zic now accepts subsecond precision in expressions like + 00:19:32.13, which is approximately the legal time of the + Netherlands from 1835 to 1937. However, because it is + questionable whether the few recorded uses of non-integer offsets + had subsecond precision in practice, there are no plans for tzdata + to use this feature. (Thanks to Steve Allen for pointing out + the limitations of historical data in this area.) + + The code is a bit more portable to MS-Windows. Installers can + compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that + reserve identifiers like 'localtime'. (Thanks to Manuela + Friedrich.) + + Changes to documentation and commentary + + theory.html now outlines tzdb's extensions to POSIX's model for + civil time, and has a section "POSIX features no longer needed" + that lists POSIX API components that are now vestigial. + (From suggestions by Steve Summit.) It also better distinguishes + time zones from tz regions. (From a suggestion by Guy Harris.) + + Commentary is now more consistent about using the phrase "daylight + saving time", to match the C name tm_isdst. Daylight saving time + need not occur in summer, and need not have a positive offset from + standard time. + + Commentary about historical transitions in Uruguay has been expanded + with links to many relevant legal documents. + (Thanks to Tim Parenti.) + + Commentary now uses some non-ASCII characters with Unicode value + less than U+0100, as they can be useful and should work even with + older editors such as XEmacs. + + +Release 2018c - 2018-01-22 23:00:44 -0800 + + Briefly: + Revert Irish changes that relied on negative SAVE values. + + Changes to tm_isdst + + Revert the 2018a change to Europe/Dublin. As before, this change + does not affect UT offsets or abbreviations; it affects only + whether timestamps are considered to be standard time or + daylight-saving time, as expressed in the tm_isdst flag of C's + struct tm type. This reversion is intended to be a temporary + workaround for problems discovered with downstream uses of + releases 2018a and 2018b, which implemented Irish time by using + negative SAVE values in the Eire rules of the 'europe' file. + Although negative SAVE values have been part of tzcode for many + years and are supported by many platforms, they were not + documented before 2018a and ICU and OpenJDK do not currently + support them. A mechanism to export data to platforms lacking + support for negative DST is planned to be developed before the + change is reapplied. (Problems reported by Deborah Goldsmith and + Stephen Colebourne.) + + Changes to past timestamps + + Japanese DST transitions (1948-1951) were Sundays at 00:00, not + Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.) + + Changes to build procedure + + The build procedure now works around mawk 1.3.3's lack of support + for character class expressions. (Problem reported by Ohyama.) + + +Release 2018b - 2018-01-17 23:24:48 -0800 + + Briefly: + Fix a packaging problem in tz2018a, which was missing 'pacificnew'. + + Changes to build procedure + + The distribution now contains the file 'pacificnew' again. + This file was inadvertently omitted in the 2018a distribution. + (Problem reported by Matias Fonzo.) + + +Release 2018a - 2018-01-12 22:29:21 -0800 + + Briefly: + São Tomé and Príncipe switched from +00 to +01. + Brazil's DST will now start on November's first Sunday. + Ireland's standard time is now in the summer, not the winter. + Use Debian-style installation locations, instead of 4.3BSD-style. + New zic option -t. + + Changes to past and future timestamps + + São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at + 01:00. (Thanks to Steffen Thorsen and Michael Deckers.) + + Changes to future timestamps + + Starting in 2018 southern Brazil will begin DST on November's + first Sunday instead of October's third Sunday. (Thanks to + Steffen Thorsen.) + + Changes to past timestamps + + A discrepancy of 4 s in timestamps before 1931 in South Sudan has + been corrected. The 'backzone' and 'zone.tab' files did not agree + with the 'africa' and 'zone1970.tab' files. (Problem reported by + Michael Deckers.) + + The abbreviation invented for Bolivia Summer Time (1931-2) is now + BST instead of BOST, to be more consistent with the convention + used for Latvian Summer Time (1918-9) and for British Summer Time. + + Changes to tm_isdst + + Change Europe/Dublin so that it observes Irish Standard Time (UT + +01) in summer and GMT (as negative daylight-saving) in winter, + instead of observing standard time (GMT) in winter and Irish + Summer Time (UT +01) in summer. This change does not affect UT + offsets or abbreviations; it affects only whether timestamps are + considered to be standard time or daylight-saving time, as + expressed in the tm_isdst flag of C's struct tm type. + (Discrepancy noted by Derick Rethans.) + + Changes to build procedure + + The default installation locations have been changed to mostly + match Debian circa 2017, instead of being designed as an add-on to + 4.3BSD circa 1986. This affects the Makefile macros TOPDIR, + TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR, + USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor + locations more precisely. (This responds to suggestions from + Brian Inglis and from Steve Summit.) + + The default installation procedure no longer creates the + backward-compatibility link US/Pacific-New, which causes + confusion during user setup (e.g., see Debian bug 815200). + Use 'make BACKWARD="backward pacificnew"' to create the link + anyway, for now. Eventually we plan to remove the link entirely. + + tzdata.zi now contains a version-number comment. + (Suggested by Tom Lane.) + + The Makefile now quotes values like BACKWARD more carefully when + passing them to the shell. (Problem reported by Zefram.) + + Builders no longer need to specify -DHAVE_SNPRINTF on platforms + that have snprintf and use pre-C99 compilers. (Problem reported + by Jon Skeet.) + + Changes to code + + zic has a new option -t FILE that specifies the location of the + file that determines local time when TZ is unset. The default for + this location can be configured via the new TZDEFAULT makefile + macro, which defaults to /etc/localtime. + + Diagnostics and commentary now distinguish UT from UTC more + carefully; see theory.html for more information about UT vs UTC. + + zic has been ported to GCC 8's -Wstringop-truncation option. + (Problem reported by Martin Sebor.) + + Changes to documentation and commentary + + The zic man page now documents the longstanding behavior that + times and years can be out of the usual range, with negative times + counting backwards from midnight and with year 0 preceding year 1. + (Problem reported by Michael Deckers.) + + The theory.html file now mentions the POSIX limit of six chars + per abbreviation, and lists alphabetic abbreviations used. + + The files tz-art.htm and tz-link.htm have been renamed to + tz-art.html and tz-link.html, respectively, for consistency with + other file names and to simplify web server configuration. + + +Release 2017c - 2017-10-20 14:49:34 -0700 + + Briefly: + Northern Cyprus switches from +03 to +02/+03 on 2017-10-29. + Fiji ends DST 2018-01-14, not 2018-01-21. + Namibia switches from +01/+02 to +02 on 2018-04-01. + Sudan switches from +03 to +02 on 2017-11-01. + Tonga likely switches from +13/+14 to +13 on 2017-11-05. + Turks & Caicos switches from -04 to -05/-04 on 2018-11-04. + A new file tzdata.zi now holds a small text copy of all data. + The zic input format has been regularized slightly. + + Changes to future timestamps + + Northern Cyprus has decided to resume EU rules starting + 2017-10-29, thus reinstituting winter time. + + Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously + predicted. (Thanks to Dominic Fok.) Adjust future predictions + accordingly. + + Namibia will switch from +01 with DST to +02 all year on + 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01 + at 02:00. (Thanks to Steffen Thorsen.) + + Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed + Atyya and Yahia Abdalla.) South Sudan is not switching, so + Africa/Juba is no longer a link to Africa/Khartoum. + + Tonga has likely ended its experiment with DST, and will not + adjust its clocks on 2017-11-05. Although Tonga has not announced + whether it will continue to observe DST, the IATA is assuming that + it will not. (Thanks to David Wade.) + + Turks & Caicos will switch from -04 all year to -05 with US DST on + 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04 + at 02:00. (Thanks to Steffen Thorsen.) + + Changes to past timestamps + + Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03. + (Thanks to Arthur David Olson.) + + Detroit did not observe DST in 1967. + + Use railway time for Asia/Kolkata before 1941, by switching to + Madras local time (UT +052110) in 1870, then to IST (UT +0530) in + 1906. Also, treat 1941-2's +0630 as DST, like 1942-5. + + Europe/Dublin's 1946 and 1947 fallback transitions occurred at + 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.) + + Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to + American time in 1892, not 1879. (Thanks to Michael Deckers.) + + Adjust the 1867 transition in Alaska to better reflect the + historical record, by changing it to occur on 1867-10-18 at 15:30 + Sitka time rather than at the start of 1867-10-17 local time. + Although strictly speaking this is accurate only for Sitka, + the rest of Alaska's blanks need to be filled in somehow. + + Fix off-by-one errors in UT offsets for Adak and Nome before 1867. + (Thanks to Michael Deckers.) + + Add 7 s to the UT offset in Asia/Yangon before 1920. + + Changes to zone names + + Remove Canada/East-Saskatchewan from the 'backward' file, as it + exceeded the 14-character limit and was an unused misnomer anyway. + + Changes to build procedure + + To support applications that prefer to read time zone data in text + form, two zic input files tzdata.zi and leapseconds are now + installed by default. The commands 'zic tzdata.zi' and 'zic -L + leapseconds tzdata.zi' can reproduce the tzdata binary files + without and with leap seconds, respectively. To prevent these two + new files from being installed, use 'make TZDATA_TEXT=', and to + suppress leap seconds from the tzdata text installation, use 'make + TZDATA_TEXT=tzdata.zi'. + + 'make BACKWARD=' now suppresses backward-compatibility names + like 'US/Pacific' that are defined in the 'backward' and + 'pacificnew' files. + + 'make check' now works on systems that lack a UTF-8 locale, + or that lack the nsgmls program. Set UTF8_LOCALE to configure + the name of a UTF-8 locale, if you have one. + + Y2K runtime checks are no longer enabled by default. Add + -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of + adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU + to disable them. (New name suggested by Brian Inglis.) + + The build procedure for zdump now works on AIX 7.1. + (Problem reported by Kees Dekker.) + + Changes to code + + zic and the reference runtime now reject multiple leap seconds + within 28 days of each other, or leap seconds before the Epoch. + As a result, support for double leap seconds, which was + obsolescent and undocumented, has been removed. Double leap + seconds were an error in the C89 standard; they have never existed + in civil timekeeping. (Thanks to Robert Elz and Bradley White for + noticing glitches in the code that uncovered this problem.) + + zic now warns about use of the obsolescent and undocumented -y + option, and about use of the obsolescent TYPE field of Rule lines. + + zic now allows unambiguous abbreviations like "Sa" and "Su" for + weekdays; formerly it rejected them due to a bug. Conversely, zic + no longer considers non-prefixes to be abbreviations; for example, + it no longer accepts "lF" as an abbreviation for "lastFriday". + Also, zic warns about the undocumented usage with a "last-" + prefix, e.g., "last-Fri". + + Similarly, zic now accepts the unambiguous abbreviation "L" for + "Link" in ordinary context and for "Leap" in leap-second context. + Conversely, zic no longer accepts non-prefixes such as "La" as + abbreviations for words like "Leap". + + zic no longer accepts leap second lines in ordinary input, or + ordinary lines in leap second input. Formerly, zic sometimes + warned about this undocumented usage and handled it incorrectly. + + The new macro HAVE_TZNAME governs whether the tzname external + variable is exported, instead of USG_COMPAT. USG_COMPAT now + governs only the external variables "timezone" and "daylight". + This change is needed because the three variables are not in the + same category: although POSIX requires tzname, it specifies the + other two variables as optional. Also, USG_COMPAT is now 1 or 0: + if not defined, the code attempts to guess it from other macros. + + localtime.c and difftime.c no longer require stdio.h, and .c files + other than zic.c no longer require sys/wait.h. + + zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.) + + Calculation of time_t extrema works around a bug in GCC 4.8.4 + (Reported by Stan Shebs and Joseph Myers.) + + zic.c no longer mistranslates formats of line numbers in non-English + locales. (Problem reported by Benno Schulenberg.) + + Several minor changes have been made to the code to make it a + bit easier to port to MS-Windows and Solaris. (Thanks to Kees + Dekker for reporting the problems.) + + Changes to documentation and commentary + + The two new files 'theory.html' and 'calendars' contain the + contents of the removed file 'Theory'. The goal is to document + tzdb theory more accessibly. + + The zic man page now documents abbreviation rules. + + tz-link.htm now covers how to apply tzdata changes to clients. + (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL. + + The leap-seconds.list URL has been updated to something that is + more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.) + +Release 2017b - 2017-03-17 07:30:38 -0700 + + Briefly: Haiti has resumed DST. + + Changes to past and future timestamps + + Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.) + + Changes to past timestamps + + Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01. + + Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430" + is one byte over the POSIX limit. (Problem reported by Derick Rethans.) + + Changes to code + + The reference localtime implementation now falls back on the + current US daylight-saving transition rules rather than the + 1987-2006 rules. This fallback occurs only when (1) the TZ + environment variable has a value like "AST4ADT" that asks + for daylight saving time but does not specify the rules, (2) there + is no file by that name, and (3) the TZDEFRULES file cannot be + loaded. (Thanks to Tom Lane.) + + +Release 2017a - 2017-02-28 00:05:36 -0800 + + Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia + discontinues DST. + + Changes to future timestamps + + Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.) + + Chile's Region of Magallanes moves from -04/-03 to -03 year-round. + Its clocks diverge from America/Santiago starting 2017-05-13 at + 23:00, hiving off a new zone America/Punta_Arenas. Although the + Chilean government says this change expires in May 2019, for now + assume it's permanent. (Thanks to Juan Correa and Deborah + Goldsmith.) This also affects Antarctica/Palmer. + + Changes to past timestamps + + Fix many entries for historical timestamps for Europe/Madrid + before 1979, to agree with tables compiled by Pere Planesas of the + National Astronomical Observatory of Spain. As a side effect, + this changes some timestamps for Africa/Ceuta before 1929, which + are probably guesswork anyway. (Thanks to Steve Allen and + Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for + correcting the 1901 transition.) + + Ecuador observed DST from 1992-11-28 to 1993-02-05. + (Thanks to Alois Treindl.) + + Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21. + (Thanks to Stepan Golosunov.) + + Changes to past and future time zone abbreviations + + Switch to numeric time zone abbreviations for South America, as + part of the ongoing project of removing invented abbreviations. + This avoids the need to invent an abbreviation for the new Chilean + new zone. Similarly, switch from invented to numeric time zone + abbreviations for Afghanistan, American Samoa, the Azores, + Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei, + Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is, + Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland, + Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia, + the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia, + Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau, + Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St + Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore, + Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and + Xinjiang; for 20-minute daylight saving time in Ghana before 1943; + for half-hour daylight saving time in Belize before 1944 and in + the Dominican Republic before 1975; and for Canary Islands before + 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for + Indian Summer Time before 1942, for Indonesia before around 1964, + for Kenya before 1960, for Liberia before 1973, for Madeira before + 1967, for Namibia before 1943, for the Netherlands in 1937-9, for + Pakistan before 1971, for Western Sahara before 1977, and for + Zaporozhye in 1880-1924. + + For Alaska time from 1900 through 1967, instead of "CAT" use the + abbreviation "AST", the abbreviation commonly used at the time + (Atlantic Standard Time had not been standardized yet). Use "AWT" + and "APT" instead of the invented abbreviations "CAWT" and "CAPT". + + Use "CST" and "CDT" instead of invented abbreviations for Macau + before 1999 and Taiwan before 1938, and use "JST" instead of the + invented abbreviation "JCST" for Japan and Korea before 1938. + + Change to database entry category + + Move the Pacific/Johnston link from 'australasia' to 'backward', + since Johnston is now uninhabited. + + Changes to code + + zic no longer mishandles some transitions in January 2038 when it + attempts to work around Qt bug 53071. This fixes a bug affecting + Pacific/Tongatapu that was introduced in zic 2016e. localtime.c + now contains a workaround, useful when loading a file generated by + a buggy zic. (Problem and localtime.c fix reported by Bradley + White.) + + zdump -i now outputs non-hour numeric time zone abbreviations + without a colon, e.g., "+0530" rather than "+05:30". This agrees + with zic %z and with common practice, and simplifies auditing of + zdump output. + + zdump is now buildable again with -DUSE_LTZ=0. + (Problem reported by Joseph Myers.) + + zdump.c now always includes private.h, to avoid code duplication + with private.h. (Problem reported by Kees Dekker.) + + localtime.c no longer mishandles early or late timestamps + when TZ is set to a POSIX-style string that specifies DST. + (Problem reported by Kees Dekker.) + + date and strftime now cause %z to generate "-0000" instead of + "+0000" when the UT offset is zero and the time zone abbreviation + begins with "-". + + Changes to documentation and commentary + + The 'Theory' file now better documents choice of historical time + zone abbreviations. (Problems reported by Michael Deckers.) + + tz-link.htm now covers leap smearing, which is popular in clouds. + + +Release 2016j - 2016-11-22 23:17:13 -0800 + + Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04. + + Changes to future timestamps + + Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00. + This hives off a new zone Europe/Saratov from Europe/Volgograd. + (Thanks to Yuri Konotopov and Stepan Golosunov.) + + Changes to past timestamps + + The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like + Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring + 1999, not fall 1994. (Thanks to Stepan Golosunov.) + + Changes to past time zone abbreviations + + Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote + summer time before 1948. The old use of "EET" was a typo. + + Changes to code + + zic no longer mishandles file systems that lack hard links, fixing + bugs introduced in 2016g. (Problems reported by Tom Lane.) + Also, when the destination already contains symbolic links, zic + should now work better on systems where the 'link' system call + does not follow symbolic links. + + Changes to documentation and commentary + + tz-link.htm now documents the relationship between release version + numbers and development-repository commit tags. (Suggested by + Paul Koning.) + + The 'Theory' file now documents UT. + + iso3166.tab now accents "Curaçao", and commentary now mentions + the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.) + + +Release 2016i - 2016-11-01 23:19:52 -0700 + + Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga + reintroduces DST on 2016-11-06. + + Changes to future timestamps + + Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on + 2017-01-15 at 03:00. Assume future observances in Tonga will be + from the first Sunday in November through the third Sunday in + January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric + time zone abbreviations for this zone. + + Changes to past and future timestamps + + Northern Cyprus is now +03 year round, causing a split in Cyprus + time zones starting 2016-10-30 at 04:00. This creates a zone + Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.) + + Antarctica/Casey switched from +08 to +11 on 2016-10-22. + (Thanks to Steffen Thorsen.) + + Changes to past timestamps + + Several corrections were made for pre-1975 timestamps in Italy. + These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and + Europe/Vatican. + + First, the 1893-11-01 00:00 transition in Italy used the new UT + offset (+01), not the old (+00:49:56). (Thanks to Michael + Deckers.) + + Second, rules for daylight saving in Italy were changed to agree + with Italy's National Institute of Metrological Research (INRiM) + except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian + Inglis, and Michael Deckers): + + The 1916-06-03 transition was at 24:00, not 00:00. + + The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at + 00:00, not 01:00. + + The 1917-09-30 and 1918-10-06 transitions were at 24:00, not + 01:00. + + The 1944-09-17 transition was at 03:00, not 01:00. This + particular change is taken from Italian law as INRiM's table, + (which says 02:00) appears to have a typo here. Also, keep the + 1944-04-03 transition for Europe/Rome, as Rome was controlled by + Germany then. + + The 1967-1970 and 1972-1974 fallback transitions were at 01:00, + not 00:00. + + Changes to code + + The code should now be buildable on AmigaOS merely by setting the + appropriate Makefile variables. (From a patch by Carsten Larsen.) + + +Release 2016h - 2016-10-19 23:17:57 -0700 + + Changes to future timestamps + + Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not + 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that + future fall transitions will be on the last Saturday of October + at 01:00, which is consistent with predicted spring transitions + on the last Saturday of March. (Thanks to Tim Parenti.) + + Changes to past timestamps + + In Turkey, transitions in 1986-1990 were at 01:00 standard time + not at 02:00, and the spring 1994 transition was on March 20, not + March 27. (Thanks to Kıvanç Yazan.) + + Changes to past and future time zone abbreviations + + Asia/Colombo now uses numeric time zone abbreviations like "+0530" + instead of alphabetic ones like "IST" and "LKT". Various + English-language sources use "IST", "LKT" and "SLST", with no + working consensus. (Usage of "SLST" mentioned by Sadika + Sumanapala.) + + Changes to code + + zic no longer mishandles relativizing file names when creating + symbolic links like /etc/localtime, when these symbolic links + are outside the usual directory hierarchy. This fixes a bug + introduced in 2016g. (Problem reported by Andreas Stieger.) + + Changes to build procedure + + New rules 'traditional_tarballs' and 'traditional_signatures' for + building just the traditional-format distribution. (Requested by + Deborah Goldsmith.) + + The file 'version' is now put into the tzdata tarball too. + (Requested by Howard Hinnant.) + + Changes to documentation and commentary + + The 'Theory' file now has a section on interface stability. + (Requested by Paul Koning.) It also mentions features like + tm_zone and localtime_rz that have long been supported by the + reference code. + + tz-link.htm has improved coverage of time zone boundaries suitable + for geolocation. (Thanks to heads-ups from Evan Siroky and Matt + Johnson.) + + The US commentary now mentions Allen and the "day of two noons". + + The Fiji commentary mentions the government's 2016-10-03 press + release. (Thanks to Raymond Kumar.) + + +Release 2016g - 2016-09-13 08:56:38 -0700 + + Changes to future timestamps + + Turkey switched from EET/EEST (+02/+03) to permanent +03, + effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather + than an invented abbreviation for the new time. + + New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52. + (Thanks to Tim Parenti.) + + Changes to past timestamps + + For America/Los_Angeles, spring-forward transition times have been + corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in + 1950-1966. + + For zones using Soviet time on 1919-07-01, transitions to UT-based + time were at 00:00 UT, not at 02:00 local time. The affected + zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and + Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.) + + Changes to past and future time zone abbreviations + + The Factory zone now uses the time zone abbreviation -00 instead + of a long English-language string, as -00 is now the normal way to + represent an undefined time zone. + + Several zones in Antarctica and the former Soviet Union, along + with zones intended for ships at sea that cannot use POSIX TZ + strings, now use numeric time zone abbreviations instead of + invented or obsolete alphanumeric abbreviations. The affected + zones are Antarctica/Casey, Antarctica/Davis, + Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera, + Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok, + Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita, + Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga, + Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin, + Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi, + Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg, + Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11, + Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5, + Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2, + Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8, + Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad, + Europe/Minsk, Europe/Samara, Europe/Volgograd, and + Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM + was replaced by +05, whereas MSK and MSD were kept as they are not + our invention and are widely used. + + Changes to zone names + + Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link. + (Thanks to David Massoud.) + + Changes to code + + zic no longer generates binary files containing POSIX TZ-like + strings that disagree with the local time type after the last + explicit transition in the data. This fixes a bug with + Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps + on the reference platform. (Thanks to Alexander Belopolsky for + reporting the bug and suggesting a way forward.) + + If the installed localtime and/or posixrules files are symbolic + links, zic now keeps them symbolic links when updating them, for + compatibility with platforms like OpenSUSE where other programs + configure these files as symlinks. + + zic now avoids hard linking to symbolic links, avoids some + unnecessary mkdir and stat system calls, and uses shorter file + names internally. + + zdump has a new -i option to generate transitions in a + smaller but still human-readable format. This option is + experimental, and the output format may change in future versions. + (Thanks to Jon Skeet for suggesting that an option was needed, + and thanks to Tim Parenti and Chris Rovick for further comments.) + + Changes to build procedure + + An experimental distribution format is available, in addition + to the traditional format which will continue to be distributed. + The new format is a tarball tzdb-VERSION.tar.lz with signature + file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory + tzdb-VERSION containing the code and data of the traditional + two-tarball format, along with extra data that may be useful. + (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others + for comments about the experimental format.) + + The release version number is now more accurate in the usual case + where releases are built from a Git repository. For example, if + 23 commits and some working-file changes have been made since + release 2016g, the version number is now something like + '2016g-23-g50556e3-dirty' instead of the misleading '2016g'. + Tagged releases use the same version number format as before, + e.g., '2016g'. To support the more accurate version number, its + specification has moved from a line in the Makefile to a new + source file 'version'. + + The experimental distribution contains a file to2050.tzs that + contains what should be the output of 'zdump -i -c 2050' on + primary zones. If this file is available, 'make check' now checks + that zdump generates this output. + + 'make check_web' now works on Fedora-like distributions. + + Changes to documentation and commentary + + tzfile.5 now documents the new restriction on POSIX TZ-like + strings that is now implemented by zic. + + Comments now cite URLs for some 1917-1921 Russian DST decrees. + (Thanks to Alexander Belopolsky.) + + tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J + (thanks to Meno Hochschild) and ThreeTen-Extra, and its + description of Java 8 has been brought up to date (thanks to + Stephen Colebourne). Its description of local time on Mars has + been updated to match current practice, and URLs have been updated + and some obsolete ones removed. + + +Release 2016f - 2016-07-05 16:26:51 +0200 + + Changes affecting future timestamps + + The Egyptian government changed its mind on short notice, and + Africa/Cairo will not introduce DST starting 2016-07-07 after all. + (Thanks to Mina Samuel.) + + Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00. + (Thanks to Stepan Golosunov.) + + Changes to past and future timestamps + + Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone + abbreviations instead of invented ones. + + Changes affecting past timestamps + + Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00. + (Thanks to Stepan Golosunov.) + + +Release 2016e - 2016-06-14 08:46:16 -0700 + + Changes affecting future timestamps + + Africa/Cairo observes DST in 2016 from July 7 to the end of October. + Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.) + For future years, guess April's last Thursday to October's last + Thursday except for Ramadan. + + Changes affecting past timestamps + + Locations while uninhabited now use '-00', not 'zzz', as a + placeholder time zone abbreviation. This is inspired by Internet + RFC 3339 and is more consistent with numeric time zone + abbreviations already used elsewhere. The change affects several + arctic and antarctic locations, e.g., America/Cambridge_Bay before + 1920 and Antarctica/Troll before 2005. + + Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was + at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.) + + Changes to code + + zic now outputs a dummy transition at time 2**31 - 1 in zones + whose POSIX-style TZ strings contain a '<'. This mostly works + around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>. + (Thanks to Zhanibek Adilbekov for reporting the Qt bug.) + + Changes affecting documentation and commentary + + tz-link.htm says why governments should give plenty of notice for + time zone or DST changes, and refers to Matt Johnson's blog post. + + tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.) + + +Release 2016d - 2016-04-17 22:50:29 -0700 + + Changes affecting future timestamps + + America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30. + (Thanks to Alexander Krivenyshev for the heads-up.) + + Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00. + (Thanks to Alexander Krivenyshev and Matt Johnson.) + + New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers + Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29 + at 02:00. (Thanks to Stepan Golosunov.) + + Changes affecting past timestamps + + New zone Europe/Kirov, split off from Europe/Volgograd. It covers + Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on + 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made + the same change. (Thanks to Stepan Golosunov.) + + Russia and nearby locations had daylight-saving transitions on + 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on + 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan + Golosunov.) + + Many corrections to historical time in Kazakhstan from 1991 + through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's + invented time zone abbreviations with numeric abbreviations. + + Changes to commentary + + Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references). + + +Release 2016c - 2016-03-23 00:51:27 -0700 + + Changes affecting future timestamps + + Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.) + + Chile reverts from permanent to seasonal DST. (Thanks to Juan + Correa for the heads-up, and to Tim Parenti for corrections.) + Guess that future transitions are August's and May's second + Saturdays at 24:00 mainland time. Also, call the period from + 2014-09-07 through 2016-05-14 daylight saving time instead of + standard time, as that seems more appropriate now. + + Changes affecting past timestamps + + Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to + +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed + from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26. + (Thanks to Stepan Golosunov.) + + Changes to commentary + + Several updates and URLs for historical and proposed Russian changes. + (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.) + + +Release 2016b - 2016-03-12 17:30:14 -0800 + + Compatibility note + + Starting with release 2016b, some data entries cause zic implementations + derived from tz releases 2005j through 2015e to issue warnings like + "time zone abbreviation differs from POSIX standard (+03)". + These warnings should not otherwise affect zic's output and can safely be + ignored on today's platforms, as the warnings refer to a restriction in + POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the + warnings is to upgrade to zic derived from tz releases 2015f and later. + + Changes affecting future timestamps + + New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and + Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on + 2016-03-27 at 02:00 local time. They need distinct zones since their + post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and + Altai Republic, Russia, which will switch from +06 to +07 on the same date + and local time. The Astrakhan change is already official; the others have + passed the first reading in the State Duma and are extremely likely. + Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00. + (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson + and Stepan Golosunov for followup.) + + As a trial of a new system that needs less information to be made up, + the new zones use numeric time zone abbreviations like "+04" + instead of invented abbreviations like "ASTT". + + Haiti will not observe DST in 2016. (Thanks to Jean Antoine via + Steffen Thorsen.) + + Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00. + (Thanks to Hannah Kreitem.) Guess future transitions will be March's last + Saturday at 01:00, not March's last Friday at 24:00. + + Changes affecting past timestamps + + Europe/Chisinau observed DST during 1990, and switched from +04 to + +03 at 1990-05-06 02:00, instead of switching from +03 to +02. + (Thanks to Stepan Golosunov.) + + 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not + KUYT/KUYST. (Thanks to Stepan Golosunov.) + + Changes to code + + tzselect's diagnostics and checking, and checktab.awk's checking, + have been improved. (Thanks to J William Piggott.) + + tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.) + + tzselect now tests Julian-date TZ settings more accurately. + (Thanks to J William Piggott.) + + Changes to commentary + + Comments in zone tables have been improved. (Thanks to J William Piggott.) + + tzselect again limits its menu comments so that menus fit on a + 24×80 alphanumeric display. + + A new web page tz-how-to.html. (Thanks to Bill Seymour.) + + In the Theory file, the description of possible time zone abbreviations in + tzdata has been cleaned up, as the old description was unclear and + inconsistent. (Thanks to Alain Mouette for reporting the problem.) + + +Release 2016a - 2016-01-26 23:28:02 -0800 + + Changes affecting future timestamps + + America/Cayman will not observe daylight saving this year after all. + Revert our guess that it would. (Thanks to Matt Johnson.) + + Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00. + (Thanks to Alexander Krivenyshev.) + + Asia/Tehran now has DST predictions for the year 2038 and later, + to be March 21 00:00 to September 21 00:00. This is likely better + than predicting no DST, albeit off by a day every now and then. + + Changes affecting past and future timestamps + + America/Metlakatla switched from PST all year to AKST/AKDT on + 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.) + + America/Santa_Isabel has been removed, and replaced with a + backward compatibility link to America/Tijuana. Its contents were + apparently based on a misreading of Mexican legislation. + + Changes affecting past timestamps + + Asia/Karachi's two transition times in 2002 were off by a minute. + (Thanks to Matt Johnson.) + + Changes affecting build procedure + + An installer can now combine leap seconds with use of the backzone file, + e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'. + The old 'make posix_packrat' rule is now marked as obsolescent. + (Thanks to Ian Abbott for an initial implementation.) + + Changes affecting documentation and commentary + + A new file LICENSE makes it easier to see that the code and data + are mostly public-domain. (Thanks to James Knight.) The three + non-public-domain files now use the current (3-clause) BSD license + instead of older versions of that license. + + tz-link.htm mentions the BDE library (thanks to Andrew Paprocki), + CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section + on editing tz source files (with a mention of Sublime zoneinfo, + thanks to Gilmore Davidson). + + The Theory and asia files now mention the 2015 book "The Global + Transformation of Time, 1870-1950", and cite a couple of reviews. + + The America/Chicago entry now documents the informal use of US + central time in Fort Pierre, South Dakota. (Thanks to Rick + McDermid, Matt Johnson, and Steve Jones.) + + +Release 2015g - 2015-10-01 00:39:51 -0700 + + Changes affecting future timestamps + + Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25. + (Thanks to Fatih.) + + Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time. + (Thanks to Alexander Krivenyshev.) + + Fiji's 2016 fall-back transition is scheduled for January 17, not 24. + (Thanks to Ken Rylander.) + + Fort Nelson, British Columbia will not fall back on 2015-11-01. It has + effectively been on MST (-0700) since it advanced its clocks on 2015-03-08. + New zone America/Fort_Nelson. (Thanks to Matt Johnson.) + + Changes affecting past timestamps + + Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00. + + Changes affecting code + + localtime no longer mishandles America/Anchorage after 2037. + (Thanks to Bradley White for reporting the bug.) + + On hosts with signed 32-bit time_t, localtime no longer mishandles + Pacific/Fiji after 2038-01-16 14:00 UTC. + + The localtime module allows the variables 'timezone', 'daylight', + and 'altzone' to be in common storage shared with other modules, + and declares them in case the system <time.h> does not. + (Problems reported by Kees Dekker.) + + On platforms with tm_zone, strftime.c now assumes it is not NULL. + This simplifies the code and is consistent with zdump.c. + (Problem reported by Christos Zoulas.) + + Changes affecting documentation + + The tzfile man page now documents that transition times denote the + starts (not the ends) of the corresponding time periods. + (Ambiguity reported by Bill Seymour.) + + +Release 2015f - 2015-08-10 18:06:56 -0700 + + Changes affecting future timestamps + + North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.) + The abbreviation remains "KST". (Thanks to Robert Elz.) + + Uruguay no longer observes DST. (Thanks to Steffen Thorsen + and Pablo Camargo.) + + Changes affecting past and future timestamps + + Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC. + (Thanks to Roman Tudos.) + + Changes affecting data format and code + + zic's '-y YEARISTYPE' option is no longer documented. The TYPE + field of a Rule line should now be '-'; the old values 'even', + 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented. + Although the implementation has not changed, these features do not + work in the default installation, they are not used in the data, + and they are now considered obsolescent. + + zic now checks that two rules don't take effect at the same time. + (Thanks to Jon Skeet and Arthur David Olson.) Constraints on + simultaneity are now documented. + + The two characters '%z' in a zone format now stand for the UT + offset, e.g., '-07' for seven hours behind UT and '+0530' for + five hours and thirty minutes ahead. This better supports time + zone abbreviations conforming to POSIX.1-2001 and later. + + Changes affecting installed data files + + Comments for America/Halifax and America/Glace_Bay have been improved. + (Thanks to Brian Inglis.) + + Data entries have been simplified for Atlantic/Canary, Europe/Simferopol, + Europe/Sofia, and Europe/Tallinn. This yields slightly smaller + installed data files for Europe/Simferopol and Europe/Tallinn. + It does not affect timestamps. (Thanks to Howard Hinnant.) + + Changes affecting code + + zdump and zic no longer warn about valid time zone abbreviations + like '-05'. + + Some Visual Studio 2013 warnings have been suppressed. + (Thanks to Kees Dekker.) + + 'date' no longer sets the time of day and its -a, -d, -n and -t + options have been removed. Long obsolescent, the implementation + of these features had porting problems. Builders no longer need + to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H. + (Thanks to Kees Dekker for pointing out the problem.) + + Changes affecting documentation + + The Theory file mentions naming issues earlier, as these seem to be + poorly publicized (thanks to Gilmore Davidson for reporting the problem). + + tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant). + + Mention that Herbert Samuel introduced the term "Summer Time". + + +Release 2015e - 2015-06-13 10:56:02 -0700 + + Changes affecting future timestamps + + Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00, + not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.) + + Assume Cayman Islands will observe DST starting next year, using US rules. + Although it isn't guaranteed, it is the most likely. + + Changes affecting data format + + The file 'iso3166.tab' now uses UTF-8, so that its entries can better + spell the names of Åland Islands, Côte d'Ivoire, and Réunion. + + Changes affecting code + + When displaying data, tzselect converts it to the current locale's + encoding if the iconv command works. (Problem reported by random832.) + + tzselect no longer mishandles Dominica, fixing a bug introduced + in Release 2014f. (Problem reported by Owen Leibman.) + + zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\". + This fixes a bug introduced in Release 2014f. + (Problem reported by Leonardo Chiquitto.) + + +Release 2015d - 2015-04-24 08:09:46 -0700 + + Changes affecting future timestamps + + Egypt will not observe DST in 2015 and will consider canceling it + permanently. For now, assume no DST indefinitely. + (Thanks to Ahmed Nazmy and Tim Parenti.) + + Changes affecting past timestamps + + America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not + 1966-07-01. Also, Yukon's time zone history is documented better. + (Thanks to Brian Inglis and Dennis Ferguson.) + + Change affecting past and future time zone abbreviations + + The abbreviations for Hawaii-Aleutian standard and daylight times + have been changed from HAST/HADT to HST/HDT, as per US Government + Printing Office style. This affects only America/Adak since 1983, + as America/Honolulu was already using the new style. + + Changes affecting code + + zic has some minor performance improvements. + + +Release 2015c - 2015-04-11 08:55:55 -0700 + + Changes affecting future timestamps + + Egypt's spring-forward transition is at 24:00 on April's last Thursday, + not 00:00 on April's last Friday. 2015's transition will therefore be on + Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes + apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.) + + Changes affecting past timestamps + + The following changes affect some pre-1991 Chile-related timestamps + in America/Santiago, Antarctica/Palmer, and Pacific/Easter. + + The 1910 transition was January 10, not January 1. + + The 1918 transition was September 10, not September 1. + + The UT -04 time observed from 1932 to 1942 is now considered to + be standard time, not year-round DST. + + Santiago observed DST (UT -03) from 1946-07-15 through + 1946-08-31, then reverted to standard time, then switched to -05 + on 1947-04-01. + + Assume transitions before 1968 were at 00:00, since we have no data + saying otherwise. + + The spring 1988 transition was 1988-10-09, not 1988-10-02. + The fall 1990 transition was 1990-03-11, not 1990-03-18. + + Assume no UT offset change for Pacific/Easter on 1890-01-01, + and omit all transitions on Pacific/Easter from 1942 through 1946 + since we have no data suggesting that they existed. + + One more zone has been turned into a link, as it differed + from an existing zone only for older timestamps. As usual, + this change affects UT offsets in pre-1970 timestamps only. + The zone's old contents have been moved to the 'backzone' file. + The affected zone is America/Montreal. + + Changes affecting commentary + + Mention the TZUpdater tool. + + Mention "The Time Now". (Thanks to Brandon Ramsey.) + + +Release 2015b - 2015-03-19 23:28:11 -0700 + + Changes affecting future timestamps + + Mongolia will start observing DST again this year, from the last + Saturday in March at 02:00 to the last Saturday in September at 00:00. + (Thanks to Ganbold Tsagaankhuu.) + + Palestine will start DST on March 28, not March 27. Also, + correct the fall 2014 transition from September 26 to October 24. + Adjust future predictions accordingly. (Thanks to Steffen Thorsen.) + + Changes affecting past timestamps + + The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a + regression. (Thanks to Stuart Bishop for reporting the problem.) + + Some more zones have been turned into links, when they differed + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. + Their old contents have been moved to the 'backzone' file. + The affected zones are: America/Antigua, America/Cayman, + Pacific/Midway, and Pacific/Saipan. + + Changes affecting time zone abbreviations + + Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD". + (Thanks to Hank W.) + + Changes affecting code + + Fix integer overflow bug in reference 'mktime' implementation. + (Problem reported by Jörg Richter.) + + Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries + to be used in the same executable as standard-library time_t functions. + (Problems reported by Bradley White.) + + Changes affecting commentary + + Cite the recent Mexican decree changing Quintana Roo's time zone. + (Thanks to Carlos Raúl Perasso.) + + Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.) + + Update info about Mars time. + + +Release 2015a - 2015-01-29 22:35:20 -0800 + + Changes affecting future timestamps + + The Mexican state of Quintana Roo, represented by America/Cancun, + will shift from Central Time with DST to Eastern Time without DST + on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.) + + Chile will not change clocks in April or thereafter; its new standard time + will be its old daylight saving time. This affects America/Santiago, + Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.) + + New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49. + (Thanks to Tim Parenti.) + + Changes affecting past timestamps + + Iceland observed DST in 1919 and 1921, and its 1939 fallback + transition was Oct. 29, not Nov. 29. Remove incorrect data from + Shanks about time in Iceland between 1837 and 1908. + + Some more zones have been turned into links, when they differed + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. + Their old contents have been moved to the 'backzone' file. + The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait, + and Asia/Muscat. + + Changes affecting code + + tzalloc now scrubs time zone abbreviations compatibly with the way + that tzset always has, by replacing invalid bytes with '_' and by + shortening too-long abbreviations. + + tzselect ports to POSIX awk implementations, no longer mishandles + POSIX TZ settings when GNU awk is used, and reports POSIX TZ + settings to the user. (Thanks to Stefan Kuhn.) + + Changes affecting build procedure + + 'make check' now checks for links to links in the data. + One such link (for Africa/Asmera) has been fixed. + (Thanks to Stephen Colebourne for pointing out the problem.) + + Changes affecting commentary + + The leapseconds file commentary now mentions the expiration date. + (Problem reported by Martin Burnicki.) + + Update Mexican Library of Congress URL. + + +Release 2014j - 2014-11-10 17:37:11 -0800 + + Changes affecting current and future timestamps + + Turks & Caicos' switch from US eastern time to UT -04 year-round + did not occur on 2014-11-02 at 02:00. It's currently scheduled + for 2015-11-01 at 02:00. (Thanks to Chris Walton.) + + Changes affecting past timestamps + + Many pre-1989 timestamps have been corrected for Asia/Seoul and + Asia/Pyongyang, based on sources for the Korean-language Wikipedia + entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no + longer guess that Pyongyang mimicked Seoul time after World War II, + as this is politically implausible. + + Some more zones have been turned into links, when they differed + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. + Their old contents have been moved to the 'backzone' file. + The affected zones are: Africa/Addis_Ababa, Africa/Asmara, + Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala, + Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and + Indian/Mayotte. + + Changes affecting commentary + + The commentary is less enthusiastic about Shanks as a source, + and is more careful to distinguish UT from UTC. + + +Release 2014i - 2014-10-21 22:04:57 -0700 + + Changes affecting future timestamps + + Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00. + (Thanks to Ken Rylander for the heads-up.) Guess that future + years will use a similar pattern. + + A new Zone Pacific/Bougainville, for the part of Papua New Guinea + that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00. + (Thanks to Kiley Walbom for the heads-up.) + + Changes affecting time zone abbreviations + + Since Belarus is not changing its clocks even though Moscow is, + the time zone abbreviation in Europe/Minsk is changing from FET + to its more traditional value MSK on 2014-10-26 at 01:00. + (Thanks to Alexander Bokovoy for the heads-up about Belarus.) + + The new abbreviation IDT stands for the pre-1976 use of UT +08 in + Indochina, to distinguish it better from ICT (+07). + + Changes affecting past timestamps + + Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976 + (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's + authoritative book). Asia/Ho_Chi_Minh has been added to + zone1970.tab, to give tzselect users in Vietnam two choices, + since north and south Vietnam disagreed after our 1970 cutoff. + + Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as + they differed from existing zones only for older timestamps. As + usual, these changes affect pre-1970 timestamps only. Their old + contents have been moved to the 'backzone' file. + + Changes affecting code + + The time-related library functions now set errno on failure, and + some crashes in the new tzalloc-related library functions have + been fixed. (Thanks to Christos Zoulas for reporting most of + these problems and for suggesting fixes.) + + If USG_COMPAT is defined and the requested timestamp is standard time, + the tz library's localtime and mktime functions now set the extern + variable timezone to a value appropriate for that timestamp; and + similarly for ALTZONE, daylight saving time, and the altzone variable. + This change is a companion to the tzname change in 2014h, and is + designed to make timezone and altzone more compatible with tzname. + + The tz library's functions now set errno to EOVERFLOW if they fail + because the result cannot be represented. ctime and ctime_r now + return NULL and set errno when a timestamp is out of range, rather + than having undefined behavior. + + Some bugs associated with the new 2014g functions have been fixed. + This includes a bug that largely incapacitated the new functions + time2posix_z and posix2time_z. (Thanks to Christos Zoulas.) + It also includes some uses of uninitialized variables after tzalloc. + The new code uses the standard type 'ssize_t', which the Makefile + now gives porting advice about. + + Changes affecting commentary + + Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis). + + +Release 2014h - 2014-09-25 18:59:03 -0700 + + Changes affecting past timestamps + + America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28. + + Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01, + not 1920-01-06. The old entry was based on a misinterpretation of Shanks. + + Some more zones have been turned into links, when they differed + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. + Their old contents have been moved to the 'backzone' file. + The affected zones are: Africa/Blantyre, Africa/Bujumbura, + Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi, + Africa/Lusaka, Africa/Maseru, and Africa/Mbabane. + + Changes affecting code + + zdump -V and -v now output gmtoff= values on all platforms, + not merely on platforms defining TM_GMTOFF. + + The tz library's localtime and mktime functions now set tzname to a value + appropriate for the requested timestamp, and zdump now uses this + on platforms not defining TM_ZONE, fixing a 2014g regression. + (Thanks to Tim Parenti for reporting the problem.) + + The tz library no longer sets tzname if localtime or mktime fails. + + zdump -c no longer mishandles transitions near year boundaries. + (Thanks to Tim Parenti for reporting the problem.) + + An access to uninitialized data has been fixed. + (Thanks to Jörg Richter for reporting the problem.) + + When THREAD_SAFE is defined, the code ports to the C11 memory model. + A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined + and two threads race to initialize data used by gmtime-like functions. + (Thanks to Andy Heninger for reporting the problems.) + + Changes affecting build procedure + + 'make check' now checks better for properly sorted data. + + Changes affecting documentation and commentary + + zdump's gmtoff=N output is now documented, and its isdst=D output + is now documented to possibly output D values other than 0 or 1. + + zdump -c's treatment of years is now documented to use the + Gregorian calendar and Universal Time without leap seconds, + and its behavior at cutoff boundaries is now documented better. + (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.) + + Programs are now documented to use the proleptic Gregorian calendar. + (Thanks to Alan Barrett for the suggestion.) + + Fractional-second GMT offsets have been documented for civil time + in 19th-century Chennai, Jakarta, and New York. + + +Release 2014g - 2014-08-28 12:31:23 -0700 + + Changes affecting future timestamps + + Turks & Caicos is switching from US eastern time to UT -04 + year-round, modeled as a switch on 2014-11-02 at 02:00. + [As noted in 2014j, this switch was later delayed.] + + Changes affecting past timestamps + + Time in Russia or the USSR before 1926 or so has been corrected by + a few seconds in the following zones: Asia/Irkutsk, + Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi, + Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For + Asia/Yekaterinburg the correction is a few minutes. (Thanks to + Vladimir Karpinsky.) + + The Portuguese decree of 1911-05-26 took effect on 1912-01-01. + This affects 1911 timestamps in Africa/Bissau, Africa/Luanda, + Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912 + GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32. + (Thanks to Stephen Colebourne for pointing to the decree.) + + Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59. + + A new file 'backzone' contains data which may appeal to + connoisseurs of old timestamps, although it is out of scope for + the tz database, is often poorly sourced, and contains some data + that is known to be incorrect. The new file is not recommended + for ordinary use and its entries are not installed by default. + (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and + Isle of Man entries.) + + Some more zones have been turned into links, when they differed + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. + Their old contents have been moved to the 'backzone' file. + The affected zones are: Africa/Bangui, Africa/Brazzaville, + Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda, + Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo. + + Changes affecting code + + Unless NETBSD_INSPIRED is defined to 0, the tz library now + supplies functions for creating and using objects that represent + timezones. The new functions are tzalloc, tzfree, localtime_rz, + mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and + time2posix_z. They are intended for performance: for example, + localtime_rz (unlike localtime_r) is trivially thread-safe without + locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired + functions, and to Alan Barrett and Jonathan Lennox for helping to + debug the change.) + + zdump now builds with the tz library unless USE_LTZ is defined to 0, + This lets zdump use tz features even if the system library lacks them. + To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0 + TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='. + + zdump now uses localtime_rz if available, as it's significantly faster, + and it can help zdump better diagnose invalid timezone names. + Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ + defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is + not available, zdump now uses localtime_r and tzset if available, + as this is a bit cleaner and faster than plain localtime. Compile + with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system + lacks these two functions. + + If THREAD_SAFE is defined to 1, the tz library is now thread-safe. + Although not needed for tz's own applications, which are single-threaded, + this supports POSIX better if the tz library is used in multithreaded apps. + + Some crashes have been fixed when zdump or the tz library is given + invalid or outlandish input. + + The tz library no longer mishandles leap seconds on platforms with + unsigned time_t in timezones that lack ordinary transitions after 1970. + + The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not + already defined, to make it easier to configure on common platforms. + Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this. + + Unless the new macro UNINIT_TRAP is defined to 1, the tz code now + assumes that reading uninitialized memory yields garbage values + but does not cause other problems such as traps. + + If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now + more likely to guess right for ambiguous timestamps near + transitions where tm_isdst does not change. + + If HAVE_STRFTIME_L is defined to 1, the tz library now defines + strftime_l for compatibility with recent versions of POSIX. + Only the C locale is supported, though. HAVE_STRFTIME_L defaults + to 1 on recent POSIX versions, and to 0 otherwise. + + tzselect -c now uses a hybrid distance measure that works better + in Africa. (Thanks to Alan Barrett for noting the problem.) + + The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used, + or when time_tz is defined. + + When HAVE_UTMPX_H is set the 'date' command now builds on systems + whose <utmpx.h> file does not define WTMPX_FILE, and when setting + the date it updates the wtmpx file if _PATH_WTMPX is defined. + This affects GNU/Linux and similar systems. + + For easier maintenance later, some C code has been simplified, + some lint has been removed, and the code has been tweaked so that + plain 'make' is more likely to work. + + The C type 'bool' is now used for boolean values, instead of 'int'. + + The long-obsolete LOCALE_HOME code has been removed. + + The long-obsolete 'gtime' function has been removed. + + Changes affecting build procedure + + 'zdump' no longer links in ialloc.o, as it's not needed. + + 'make check_time_t_alternatives' no longer assumes GNU diff. + + Changes affecting distribution tarballs + + The files checktab.awk and zoneinfo2tdf.pl are now distributed in + the tzdata tarball instead of the tzcode tarball, since they help + maintain the data. The NEWS and Theory files are now also + distributed in the tzdata tarball, as they're relevant for data. + (Thanks to Alan Barrett for pointing this out.) Also, the + leapseconds.awk file is no longer distributed in the tzcode + tarball, since it belongs in the tzdata tarball (where 2014f + inadvertently also distributed it). + + Changes affecting documentation and commentary + + A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for + suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms + for debugging it.) + + The man pages have been updated to use function prototypes, + to document thread-safe variants like localtime_r, and to document + the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and + mktime_z. + + The fields in Link lines have been renamed to be more descriptive + and more like the parameters of 'ln'. LINK-FROM has become TARGET, + and LINK-TO has become LINK-NAME. + + tz-link.htm mentions the IETF's tzdist working group; Windows + Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab. + + Some broken URLs have been fixed in the commentary. (Thanks to + Lester Caine.) + + Commentary about Philippines DST has been updated, and commentary + on pre-1970 time in India has been added. + + +Release 2014f - 2014-08-05 17:42:36 -0700 + + Changes affecting future timestamps + + Russia will subtract an hour from most of its time zones on 2014-10-26 + at 02:00 local time. (Thanks to Alexander Krivenyshev.) + There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky + Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug + (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast + (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic + (Europe/Samara) are not changing their clocks. The changed zones are + Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd, + Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk, + Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga, + Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours + subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected, + but not its UTC offset. Two zones are added: Asia/Chita (split + from Asia/Yakutsk, and also with two hours subtracted) and + Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour + subtracted). (Thanks to Tim Parenti for much of the above.) + + Changes affecting time zone abbreviations + + Australian eastern time zone abbreviations are now AEST/AEDT not EST, + and similarly for the other Australian zones. That is, for eastern + standard and daylight saving time the abbreviations are AEST and AEDT + instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT, + and AWST/AWDT are now used instead of the former CST, CWST, and WST. + This change does not affect UT offsets, only time zone abbreviations. + (Thanks to Rich Tibbett and many others.) + + Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07) + effective 2014-10-26 at 02:00 local time. + + The time zone abbreviation for Xinjiang Time (observed in Ürümqi) + has been changed from URUT to XJT. (Thanks to Luther Ma.) + + Prefer MSK/MSD for Moscow time in Russia, even in other cities. + Similarly, prefer EET/EEST for eastern European time in Russia. + + Change time zone abbreviations in (western) Samoa to use "ST" and + "DT" suffixes, as this is more likely to match common practice. + Prefix "W" to (western) Samoa time when its standard-time offset + disagrees with that of American Samoa. + + America/Metlakatla now uses PST, not MeST, to abbreviate its time zone. + + Time zone abbreviations have been updated for Japan's two time + zones used 1896-1937. JWST now stands for Western Standard + Time, and JCST for Central Standard Time (formerly this was CJT). + These abbreviations are now used for time in Korea, Taiwan, + and Sakhalin while controlled by Japan. + + Changes affecting past timestamps + + China's five zones have been simplified to two, since the post-1970 + differences in the other three seem to have been imaginary. The + zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been + removed; backwards-compatibility links still work, albeit with + different behaviors for timestamps before May 1980. Asia/Urumqi's + 1980 transition to UT +08 has been removed, so that it is now at + +06 and not +08. (Thanks to Luther Ma and to Alois Treindl; + Treindl sent helpful translations of two papers by Guo Qingsheng.) + + Some zones have been turned into links, when they differed from existing + zones only for older UT offsets where data entries were likely invented. + These changes affect UT offsets in pre-1970 timestamps only. This is + similar to the change in release 2013e, except this time for western + Africa. The affected zones are: Africa/Bamako, Africa/Banjul, + Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome, + Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and + Atlantic/St_Helena. This also affects the backwards-compatibility + link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne, + Tim Parenti, and David Patte for reporting problems in earlier + versions of this change.) + + Asia/Shanghai's pre-standard-time UT offset has been changed from + 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its + transition to standard time has been changed from 1928 to 1901. + + Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01, + then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945. + In 1946 it observed DST from 05-15 through 09-30; in 1947 + from 04-15 through 10-31; and in 1979 from 07-01 through 09-30. + (Thanks to Yu-Cheng Chuang.) + + Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950. + + Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not + 10-03 at 00:00. (Thanks to Konstantin Hyppönen.) + + Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the + period from 1911 to 1950. + + Pacific/Chatham has been changed to New Zealand standard time plus + 45 minutes for the period before 1957, reflecting a 1956 remark in + the New Zealand parliament. + + Europe/Budapest has several pre-1946 corrections: in 1918 the transition + out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in + 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08 + not 04-06 at 02:00; and there was no DST in 1920. + + Africa/Accra is now assumed to have observed DST from 1920 through 1935. + + Time in Russia before 1927 or so has been corrected by a few seconds in + the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi, + Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and + Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0 + point. (Thanks to Vladimir Karpinsky for the Moscow changes.) + + Changes affecting data format + + A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data. + The new file's extended format allows multiple country codes per zone. + The older file is still installed but is deprecated; its format is + not changing and it will still be distributed for a while, but new + applications should use the new file. + + The new file format simplifies maintenance of obscure locations. + To test this, it adds coverage for the Crozet Islands and the + Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.) + + The file 'iso3166.tab' is planned to switch from ASCII to UTF-8. + It is still ASCII now, but commentary about the switch has been added. + The new file 'zone1970.tab' already uses UTF-8. + + Changes affecting code + + 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE + is defined. (Thanks to Elliott Hughes for reporting the problem.) + + 'zic' no longer mishandles input when ignoring case in locales that + are not compatible with English, e.g., unibyte Turkish locales when + compiled with HAVE_GETTEXT. + + Error diagnostics of 'zic' and 'yearistype' have been reworded so that + they no longer use ASCII '-' as if it were a dash. + + 'zic' now rejects output file names that contain '.' or '..' components. + (Thanks to Tim Parenti for reporting the problem.) + + 'zic -v' now warns about output file names that do not follow + POSIX rules, or that contain a digit or '.'. (Thanks to Arthur + David Olson for starting the ball rolling on this.) + + Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0. + + Changes affecting build procedure + + 'zic' no longer links in localtime.o and asctime.o, as they're not needed. + (Thanks to John Cochran.) + + Changes affecting documentation and commentary + + The 'Theory' file documents legacy names, the longstanding + exceptions to the POSIX-inspired file name rules. + + The 'zic' documentation clarifies the role of time types when + interpreting dates. (Thanks to Arthur David Olson.) + + Documentation and commentary now prefer UTF-8 to US-ASCII, + allowing the use of proper accents in foreign words and names. + Code and data have not changed because of this. (Thanks to + Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug + this.) + + Non-HTML documentation and commentary now use plain-text URLs instead of + HTML insertions, and are more consistent about bracketing URLs when they + are not already surrounded by white space. (Thanks to suggestions by + Steffen Nurpmeso.) + + There is new commentary about Xujiahui Observatory, the five time-zone + project in China from 1918 to 1949, timekeeping in Japanese-occupied + Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the + warlord Jin Shuren in the data. + + Commentary about the coverage of each Russian zone has been standardized. + (Thanks to Tim Parenti.) + + There is new commentary about contemporary timekeeping in Ethiopia. + + Obsolete comments about a 2007 proposal for DST in Kuwait has been removed. + + There is new commentary about time in Poland in 1919. + + Proper credit has been given to DST inventor George Vernon Hudson. + + Commentary about time in Metlakatla, AK and Resolute, NU has been + improved, with a new source for the former. + + In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it + is uninhabited. + + Commentary about permanent Antarctic bases has been updated. + + Several typos have been corrected. (Thanks to Tim Parenti for + contributing some of these fixes.) + + tz-link.htm now mentions the JavaScript libraries Moment Timezone, + TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up + from Matt Johnson.) Also, it mentions the Go 'latlong' package. + (Thanks to a heads-up from Dirkjan Ochtman.) + + The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998 + have been removed. These obsolescent US Naval Observatory entries were no + longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.) + + +Release 2014e - 2014-06-12 21:53:52 -0700 + + Changes affecting near-future timestamps + + Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00. + (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily + switch to standard time at 24:00 the last Thursday before Ramadan, and + back to DST at 00:00 the first Friday after Ramadan. + + Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks + to Milamber Space Network.) Guess that from 2015 on Morocco will + temporarily switch to standard time at 03:00 the last Saturday before + Ramadan, and back to DST at 02:00 the first Saturday after Ramadan. + + Changes affecting past timestamps + + The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of + "MSD" for Moscow's double daylight time in summer 1921. Also, a typo + "VLASST" has been repaired to be "VLAST" for Vladivostok summer time + in 1991. (Thanks to Hank W. for reporting the problems.) + + Changes affecting commentary + + tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the + draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and + removes stale pointers to World Time Explorer and WORLDTIME. + + +Release 2014d - 2014-05-27 21:34:40 -0700 + + Changes affecting code + + zic no longer generates files containing timestamps before the Big Bang. + This works around GNOME glib bug 878 + <https://gitlab.gnome.org/GNOME/glib/issues/878> + (Thanks to Leonardo Chiquitto for reporting the bug, and to + Arthur David Olson and James Cloos for suggesting improvements to the fix.) + + Changes affecting documentation + + tz-link.htm now mentions GNOME. + + +Release 2014c - 2014-05-13 07:44:13 -0700 + + Changes affecting near-future timestamps + + Egypt observes DST starting 2014-05-15 at 24:00. + (Thanks to Ahmad El-Dardiry and Gunther Vermier.) + Details have not been announced, except that DST will not be observed + during Ramadan. Guess that DST will stop during the same Ramadan dates as + Morocco, and that Egypt's future spring and fall transitions will be the + same as 2010 when it last observed DST, namely April's last Friday at + 00:00 to September's last Thursday at 23:00 standard time. Also, guess + that Ramadan transitions will be at 00:00 standard time. + + Changes affecting code + + zic now generates transitions for minimum time values, eliminating guesswork + when handling low-valued timestamps. (Thanks to Arthur David Olson.) + + Port to Cygwin sans glibc. (Thanks to Arthur David Olson.) + + Changes affecting commentary and documentation + + Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.) + + +Release 2014b - 2014-03-24 21:28:50 -0700 + + Changes affecting near-future timestamps + + Crimea switches to Moscow time on 2014-03-30 at 02:00 local time. + (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU. + + New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and + Bengt-Inge Larsson.) This is currently an approximation; a better version + will require the zic and localtime fixes mentioned below, and the plan is + to wait for a while until at least the zic fixes propagate. + + Changes affecting code + + 'zic' and 'localtime' no longer reject locations needing four transitions + per year for the foreseeable future. (Thanks to Andrew Main (Zefram).) + Also, 'zic' avoids some unlikely failures due to integer overflow. + + Changes affecting build procedure + + 'make check' now detects Rule lines defined but never used. + The NZAQ rules, an instance of this problem, have been removed. + + Changes affecting commentary and documentation + + Fix Tuesday/Thursday typo in description of time in Israel. + (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.) + + Microsoft Windows 8.1 doesn't support tz database names. (Thanks + to Donald MacQueen.) Instead, the Microsoft Windows Store app + library supports them. + + Add comments about Johnston Island time in the 1960s. + (Thanks to Lyle McElhaney.) + + Morocco's 2014 DST start will be as predicted. + (Thanks to Sebastien Willemijns.) + + +Release 2014a - 2014-03-07 23:30:29 -0800 + + Changes affecting near-future timestamps + + Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for + the heads-up, and to Tim Parenti for simplifying the update.) + + Changes affecting past timestamps + + Fiji ended DST on 2014-01-19 at 02:00, not the previously scheduled 03:00. + (Thanks to Steffen Thorsen.) + + Ukraine switched from Moscow to Eastern European time on 1990-07-01 + (not 1992-01-01), and observed DST during the entire next winter. + (Thanks to Vladimir in Moscow via Alois Treindl.) + + In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03. + (Thanks to Avigdor Finkelstein.) + + Changes affecting code + + A uninitialized-storage bug in 'localtime' has been fixed. + (Thanks to Logan Chien.) + + Changes affecting the build procedure + + The settings for 'make check_web' now default to Ubuntu 13.10. + + Changes affecting commentary and documentation + + The boundary of the US Pacific time zone is given more accurately. + (Thanks to Alan Mintz.) + + Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.) + + Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.) + + Better descriptions of countries with same time zone history as + Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.) + + Several changes affect tz-link.htm, the main web page. + + Mention Time.is (thanks to Even Scharning) and WX-now (thanks to + David Braverman). + + Mention xCal (Internet RFC 6321) and jCal. + + Microsoft has some support for tz database names. + + CLDR data formats include both XML and JSON. + + Mention Maggiolo's map of solar vs standard time. + (Thanks to Arthur David Olson.) + + Mention TZ4Net. (Thanks to Matt Johnson.) + + Mention the timezone-olson Haskell package. + + Mention zeitverschiebung.net. (Thanks to Martin Jäger.) + + Remove moribund links to daylight-savings-time.info and to + Simple Timer + Clocks. + + Update two links. (Thanks to Oscar van Vlijmen.) + + Fix some formatting glitches, e.g., remove random newlines from + abbr elements' title attributes. + + +Release 2013i - 2013-12-17 07:25:23 -0800 + + Changes affecting near-future timestamps: + + Jordan switches back to standard time at 00:00 on December 20, 2013. + The 2006-2011 transition schedule is planned to resume in 2014. + (Thanks to Steffen Thorsen.) + + Changes affecting past timestamps: + + In 2004, Cuba began DST on March 28, not April 4. + (Thanks to Steffen Thorsen.) + + Changes affecting code + + The compile-time flag NOSOLAR has been removed, as nowadays the + benefit of slightly shrinking runtime table size is outweighed by the + cost of disallowing potential future updates that exceed old limits. + + Changes affecting documentation and commentary + + The files solar87, solar88, and solar89 are no longer distributed. + They were a negative experiment - that is, a demonstration that + tz data can represent solar time only with some difficulty and error. + Their presence in the distribution caused confusion, as Riyadh + civil time was generally not solar time in those years. + + tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.) + + +Release 2013h - 2013-10-25 15:32:32 -0700 + + Changes affecting current and future timestamps: + + Libya has switched its UT offset back to +02 without DST, instead + of +01 with DST. (Thanks to Even Scharning.) + + Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules. + (Thanks to Gwillim Law.) + + Changes affecting future timestamps: + + Acre and (we guess) western Amazonas will switch from UT -04 to -05 + on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe. + (Thanks to Steffen Thorsen.) + + Add entries for DST transitions in Morocco in the year 2038. + This avoids some year-2038 glitches introduced in 2013g. + (Thanks to Yoshito Umaoka for reporting the problem.) + + Changes affecting API + + The 'tzselect' command no longer requires the 'select' command, + and should now work with /bin/sh on more platforms. It also works + around a bug in BusyBox awk before version 1.21.0. (Thanks to + Patrick 'P. J.' McDermott and Alan Barrett.) + + Changes affecting code + + Fix localtime overflow bugs with 32-bit unsigned time_t. + + zdump no longer assumes sscanf returns maximal values on overflow. + + Changes affecting the build procedure + + The builder can specify which programs to use, if any, instead of + 'ar' and 'ranlib', and libtz.a is now built locally before being + installed. (Thanks to Michael Forney.) + + A dependency typo in the 'zdump' rule has been fixed. + (Thanks to Andrew Paprocki.) + + The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f' + work as specified by POSIX.2-1992 or later; this is portable nowadays. + + 'make clean' no longer removes 'leapseconds', since it's + host-independent and is part of the distribution. + + The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed. + + Changes affecting documentation and commentary + + tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol + (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle). + + Update URLs in tz-link page. Add URLs for Microsoft Windows, since + 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no + longer maintained) and for old advisories. SOFA now does C. + +Release 2013g - 2013-09-30 21:08:26 -0700 + + Changes affecting current and near-future timestamps + + Morocco now observes DST from the last Sunday in March to the last + Sunday in October, not April to September respectively. (Thanks + to Steffen Thorsen.) + + Changes affecting 'zic' + + 'zic' now runs on platforms that lack both hard links and symlinks. + (Thanks to Theo Veenker for reporting the problem, for MinGW.) + Also, fix some bugs on platforms that lack hard links but have symlinks. + + 'zic -v' again warns that Asia/Tehran has no POSIX environment variable + to predict the far future, fixing a bug introduced in 2013e. + + Changes affecting the build procedure + + The 'leapseconds' file is again put into the tzdata tarball. + Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to + Matt Burgess and Ian Abbott.) The timestamps of these and other + dependent files in tarballs are adjusted more consistently. + + Changes affecting documentation and commentary + + The README file is now part of the data tarball as well as the code. + It now states that files are public domain unless otherwise specified. + (Thanks to Andrew Main (Zefram) for asking for clarifications.) + Its details about the 1989 release moved to a place of honor near + the end of NEWS. + + +Release 2013f - 2013-09-24 23:37:36 -0700 + + Changes affecting near-future timestamps + + Tocantins will very likely not observe DST starting this spring. + (Thanks to Steffen Thorsen.) + + Jordan will likely stay at UT +03 indefinitely, and will not fall + back this fall. + + Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.) + + Changes affecting API + + The types of the global variables 'timezone' and 'altzone' (if present) + have been changed back to 'long'. This is required for 'timezone' + by POSIX, and for 'altzone' by common practice, e.g., Solaris 11. + These variables were originally 'long' in the tz code, but were + mistakenly changed to 'time_t' in 1987; nobody reported the + incompatibility until now. The difference matters on x32, where + 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.) + + Changes affecting the build procedure + + Avoid long strings in leapseconds.awk to work around a mawk bug. + (Thanks to Cyril Baurand.) + + Changes affecting documentation and commentary + + New file 'NEWS' that contains release notes like this one. + + Paraguay's law does not specify DST transition time; 00:00 is customary. + (Thanks to Waldemar Villamayor-Venialbo.) + + Minor capitalization fixes. + + Changes affecting version-control only + + The experimental GitHub repository now contains annotated and + signed tags for recent releases, e.g., '2013e' for Release 2013e. + Releases are tagged starting with 2012e; earlier releases were + done differently, and tags would either not have a simple name or + not exactly match what was released. + + 'make set-timestamps' is now simpler and a bit more portable. + + +Release 2013e - 2013-09-19 23:50:04 -0700 + + Changes affecting near-future timestamps + + This year Fiji will start DST on October 27, not October 20. + (Thanks to David Wheeler for the heads-up.) For now, guess that + Fiji will continue to spring forward the Sunday before the fourth + Monday in October. + + Changes affecting current and future time zone abbreviations + + Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian + time zone abbreviations since 1932. (Thanks to George Ziegler, + Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and + Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura, + Asia/Makassar, and Asia/Pontianak. + + Use ART (UT -03, standard time), rather than WARST (also -03, but + daylight saving time) for San Luis, Argentina since 2009. + + Changes affecting Godthåb timestamps after 2037 if version mismatch + + Allow POSIX-like TZ strings where the transition time's hour can + range from -167 through 167, instead of the POSIX-required 0 + through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the + new Fiji rules. This is a more compact way to represent + far-future timestamps for America/Godthab, America/Santiago, + Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem, + Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by + this change. (Derived from a suggestion by Arthur David Olson.) + + Allow POSIX-like TZ strings where daylight saving time is in + effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western + Argentina Summer Time all year. This supports a more compact way + to represent the 2013d data for America/Argentina/San_Luis. + Because of the change for San Luis noted above this change does not + affect the current data. (Thanks to Andrew Main (Zefram) for + suggestions that improved this change.) + + Where these two TZ changes take effect, there is a minor extension + to the tz file format in that it allows new values for the + embedded TZ-format string, and the tz file format version number + has therefore been increased from 2 to 3 as a precaution. + Version-2-based client code should continue to work as before for + all timestamps before 2038. Existing version-2-based client code + (tzcode, GNU/Linux, Solaris) has been tested on version-3-format + files, and typically works in practice even for timestamps after + 2037; the only known exception is America/Godthab. + + Changes affecting timestamps before 1970 + + Pacific/Johnston is now a link to Pacific/Honolulu. This corrects + some errors before 1947. + + Some zones have been turned into links, when they differ from existing + zones only in older data entries that were likely invented or that + differ only in LMT or transitions from LMT. These changes affect + only timestamps before 1943. The affected zones are: + Africa/Juba, America/Anguilla, America/Aruba, America/Dominica, + America/Grenada, America/Guadeloupe, America/Marigot, + America/Montserrat, America/St_Barthelemy, America/St_Kitts, + America/St_Lucia, America/St_Thomas, America/St_Vincent, + America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for + confirming that the old Europe/Vaduz zone was wrong and the new + link is better for WWII-era times.) + + Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects + America/Cayman, America/Jamaica and America/Grand_Turk timestamps + from 1890 to 1912. + + Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46. + This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks + to Alois Treindl.) + + Change the date of the circa-1850 Zurich transition from 1849-09-12 + to 1853-07-16, overriding Shanks with data from Messerli about + postal and telegraph time in Switzerland. + + Changes affecting time zone abbreviations before 1970 + + For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932, + as Jakarta was called Batavia back then. + + Changes affecting API + + The 'zic' command now outputs a dummy transition when far-future + data can't be summarized using a TZ string, and uses a 402-year + window rather than a 400-year window. For the current data, this + affects only the Asia/Tehran file. It does not affect any of the + timestamps that this file represents, so zdump outputs the same + information as before. (Thanks to Andrew Main (Zefram).) + + The 'date' command has a new '-r' option, which lets you specify + the integer time to display, a la FreeBSD. + + The 'tzselect' command has two new options '-c' and '-n', which lets you + select a zone based on latitude and longitude. + + The 'zic' command's '-v' option now warns about constructs that + require the new version-3 binary file format. (Thanks to Arthur + David Olson for the suggestion.) + + Support for floating-point time_t has been removed. + It was always dicey, and POSIX no longer requires it. + (Thanks to Eric Blake for suggesting to the POSIX committee to + remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy + Heninger, Arthur David Olson, and Alois Treindl, for reporting + bugs and elucidating some of the corners of the old floating-point + implementation.) + + The signatures of 'offtime', 'timeoff', and 'gtime' have been + changed back to the old practice of using 'long' to represent UT + offsets. This had been inadvertently and mistakenly changed to + 'int_fast32_t'. (Thanks to Christos Zoulas.) + + The code avoids undefined behavior on integer overflow in some + more places, including gmtime, localtime, mktime and zdump. + + Changes affecting the zdump utility + + zdump now outputs "UT" when referring to Universal Time, not "UTC". + "UTC" does not make sense for timestamps that predate the introduction + of UTC, whereas "UT", a more generic term, does. (Thanks to Steve Allen + for clarifying UT vs UTC.) + + Data changes affecting behavior of tzselect and similar programs + + Country code BQ is now called the more common name "Caribbean Netherlands" + rather than the more official "Bonaire, St Eustatius & Saba". + + Remove from zone.tab the names America/Montreal, America/Shiprock, + and Antarctica/South_Pole, as they are equivalent to existing + same-country-code zones for post-1970 timestamps. The data entries for + these names are unchanged, so the names continue to work as before. + + Changes affecting code internals + + zic -c now runs way faster on 64-bit hosts when given large numbers. + + zic now uses vfprintf to avoid allocating and freeing some memory. + + tzselect now computes the list of continents from the data, + rather than have it hard-coded. + + Minor changes pacify GCC 4.7.3 and GCC 4.8.1. + + Changes affecting the build procedure + + The 'leapseconds' file is now generated automatically from a + new file 'leap-seconds.list', which is a copy of + <ftp://ftp.nist.gov/pub/time/leap-seconds.list> + A new source file 'leapseconds.awk' implements this. + The goal is simplification of the future maintenance of 'leapseconds'. + + When building the 'posix' or 'right' subdirectories, if the + subdirectory would be a copy of the default subdirectory, it is + now made a symbolic link if that is supported. This saves about + 2 MB of file system space. + + The links America/Shiprock and Antarctica/South_Pole have been + moved to the 'backward' file. This affects only nondefault builds + that omit 'backward'. + + Changes affecting version-control only + + .gitignore now ignores 'date'. + + Changes affecting documentation and commentary + + Changes to the 'tzfile' man page + + It now mentions that the binary file format may be extended in + future versions by appending data. + + It now refers to the 'zdump' and 'zic' man pages. + + Changes to the 'zic' man page + + It lists conditions that elicit a warning with '-v'. + + It says that the behavior is unspecified when duplicate names + are given, or if the source of one link is the target of another. + + Its examples are updated to match the latest data. + + The definition of white space has been clarified slightly. + (Thanks to Michael Deckers.) + + Changes to the 'Theory' file + + There is a new section about the accuracy of the tz database, + describing the many ways that errors can creep in, and + explaining why so many of the pre-1970 timestamps are wrong or + misleading (thanks to Steve Allen, Lester Caine, and Garrett + Wollman for discussions that contributed to this). + + The 'Theory' file describes LMT better (this follows a + suggestion by Guy Harris). + + It refers to the 2013 edition of POSIX rather than the 2004 edition. + + It's mentioned that excluding 'backward' should not affect the + other data, and it suggests at least one zone.tab name per + inhabited country (thanks to Stephen Colebourne). + + Some longstanding restrictions on names are documented, e.g., + 'America/New_York' precludes 'America/New_York/Bronx'. + + It gives more reasons for the 1970 cutoff. + + It now mentions which time_t variants are supported, such as + signed integer time_t. (Thanks to Paul Goyette for reporting + typos in an experimental version of this change.) + + (Thanks to Philip Newton for correcting typos in these changes.) + + Documentation and commentary is more careful to distinguish UT in + general from UTC in particular. (Thanks to Steve Allen.) + + Add a better source for the Zurich 1894 transition. + (Thanks to Pierre-Yves Berger.) + + Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.) + + +Release 2013d - 2013-07-05 07:38:01 -0700 + + Changes affecting future timestamps: + + Morocco's midsummer transitions this year are July 7 and August 10, + not July 9 and August 8. (Thanks to Andrew Paprocki.) + + Israel now falls back on the last Sunday of October. + (Thanks to Ephraim Silverberg.) + + Changes affecting past timestamps: + + Specify Jerusalem's location more precisely; this changes the pre-1880 + times by 2 s. + + Changing affecting metadata only: + + Fix typos in the entries for country codes BQ and SX. + + Changes affecting code: + + Rework the code to fix a bug with handling Australia/Macquarie on + 32-bit hosts (thanks to Arthur David Olson). + + Port to platforms like NetBSD, where time_t can be wider than long. + + Add support for testing time_t types other than the system's. + Run 'make check_time_t_alternatives' to try this out. + Currently, the tests fail for unsigned time_t; + this should get fixed at some point. + + Changes affecting documentation and commentary: + + Deemphasize the significance of national borders. + + Update the zdump man page. + + Remove obsolete NOID comment (thanks to Denis Excoffier). + + Update several URLs and comments in the web pages. + + Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler). + + Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka). + + +Release 2013c - 2013-04-19 16:17:40 -0700 + + Changes affecting current and future timestamps: + + Palestine observed DST starting March 29, 2013. (Thanks to + Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST, + with the predicted rules being the last Thursday in March at 24:00 + to the first Friday on or after September 21 at 01:00. + + Assume that the recent change to Paraguay's DST rules is permanent, + by moving the end of DST to the 4th Sunday in March every year. + (Thanks to Carlos Raúl Perasso.) + + Changes affecting past timestamps: + + Fix some historical data for Palestine to agree with that of + timeanddate.com, as follows: + + The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not + 00:00 Apr 1. + + The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not + 02:00. + + The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27. + + The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2. + + The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01. + + The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00. + + Fix times of habitation for Macquarie to agree with the Tasmania + Parks & Wildlife Service history, which indicates that permanent + habitation was 1899-1919 and 1948 on. + + Changing affecting metadata only: + + Macquarie Island is politically part of Australia, not Antarctica. + (Thanks to Tobias Conradi.) + + Sort Macquarie more consistently with other parts of Australia. + (Thanks to Tim Parenti.) + + +Release 2013b - 2013-03-10 22:33:40 -0700 + + Changes affecting current and future timestamps: + + Haiti uses US daylight-saving rules this year, and presumably future years. + This changes timestamps starting today. (Thanks to Steffen Thorsen.) + + Paraguay will end DST on March 24 this year. + (Thanks to Steffen Thorsen.) For now, assume it's just this year. + + Morocco does not observe DST during Ramadan; + try to predict Ramadan in Morocco as best we can. + (Thanks to Erik Homoet for the heads-up.) + + Changes affecting commentary: + + Update URLs in tz-link page. Add URLs for webOS, BB10, iOS. + Update URL for Solaris. Mention Internet RFC 6557. + Update Internet RFCs 2445->5545, 2822->5322. + Switch from FTP to HTTP for Internet RFCs. + + +Release 2013a - 2013-02-27 09:20:35 -0800 + + Change affecting binary data format: + + The zone offset at the end of version-2-format zone files is now + allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.) + + Changes affecting current and future timestamps: + + Chile's 2013 rules, and we guess rules for 2014 and later, will be + the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC. + (Thanks to Steffen Thorsen and Robert Elz.) + + New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen. + (Thanks to Tobias Conradi and Arthur David Olson.) + + Many changes affect historical timestamps before 1940. + These were deduced from: Milne J. Civil time. Geogr J. 1899 + Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>. + + Changes affecting the code: + + Fix zic bug that mishandled Egypt's 2010 changes (this also affected + the data). (Thanks to Arthur David Olson.) + + Fix localtime bug when time_t is unsigned and data files were generated + by a signed time_t system. (Thanks to Doug Bailey for reporting and + to Arthur David Olson for fixing.) + + Allow the email address for bug reports to be set by the packager. + The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.) + + Update HTML checking to be compatible with Ubuntu 12.10. + + Check that files are a safe subset of ASCII. At some point we may + relax this requirement to a safe subset of UTF-8. Without the + check, some non-UTF-8 encodings were leaking into the distribution. + + Commentary changes: + + Restore a comment about copyright notices that was inadvertently deleted. + (Thanks to Arthur David Olson.) + + Improve the commentary about which districts observe what times + in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.) + + Add web page links to tz.js. + + Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.) + + +Release 2012j - 2012-11-12 18:34:49 -0800 + + Libya moved to CET this weekend, but with DST planned next year. + (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.) + + Signatures now have the extension .asc, not .sign, as that's more + standard. (Thanks to Phil Pennock.) + + The output of 'zdump --version', and of 'zic --version', now + uses a format that is more typical for --version. + (Thanks to Joseph S. Myers.) + + The output of 'tzselect --help', 'zdump --help', and 'zic --help' + now uses tz@iana.org rather than the old elsie address. + + zic -v now complains about abbreviations that are less than 3 + or more than 6 characters, as per POSIX. Formerly, it checked + for abbreviations that were more than 3. + + 'make public' no longer puts its temporary directory under /tmp, + and uses the just-built zic rather than the system zic. + + Various fixes to documentation and commentary. + + +Release 2012i - 2012-11-03 12:57:09 -0700 + + Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.) + + Linker flags can now be specified via LDFLAGS. + AWK now defaults to 'awk', not 'nawk'. + The shell in tzselect now defaults to /bin/bash, but this can + be overridden by specifying KSHELL. + The main web page now mentions the unofficial GitHub repository. + (Thanks to Mike Frysinger.) + + Tarball signatures can now be built by running 'make signatures'. + There are also new makefile rules 'tarballs', 'check_public', and + separate makefile rules for each tarball and signature file. + A few makefile rules are now more portable to strict POSIX. + + The main web page now lists the canonical IANA URL. + + +Release 2012h - 2012-10-26 22:49:10 -0700 + + Bahia no longer has DST. (Thanks to Kelley Cook.) + + Tocantins has DST. (Thanks to Rodrigo Severo.) + + Israel has new DST rules next year. (Thanks to Ephraim Silverberg.) + + Jordan stays on DST this winter. (Thanks to Steffen Thorsen.) + + Web page updates. + + More C modernization, except that at Arthur David Olson's suggestion + the instances of 'register' were kept. + + +Release 2012g - 2012-10-17 20:59:45 -0700 + + Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.) + + Palestine fall 2012. (Thanks to Steffen Thorsen.) + + Assume C89. + + To attack the version-number problem, this release ships the file + 'Makefile' (which contains the release number) in both the tzcode and + the tzdata tarballs. The two Makefiles are identical, and should be + identical in any matching pair of tarballs, so it shouldn't matter + which order you extract the tarballs. Perhaps we can come up with a + better version-number scheme at some point; this scheme does have the + virtue of not adding more files. + + +Release 2012f - 2012-09-12 23:17:03 -0700 + + * australasia (Pacific/Fiji): Fiji DST is October 21 through January + 20 this year. (Thanks to Steffen Thorsen.) + + +Release 2012e - 2012-08-02 20:44:55 -0700 + + * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14. + (Thanks to Steffen Thorsen.) + + * Use a single version number for both code and data. + + * .gitignore: New file. + + * Remove trailing white space. + + +Release code2012c-data2012d - 2012-07-19 16:35:33 -0700 + + Changes for Morocco's timestamps, which take effect in a couple of + hours, along with infrastructure changes to accommodate how the tz + code and data are released on IANA. + + +Release data2012c - 2012-03-27 12:17:25 -0400 + + africa + Summer time changes for Morocco (to start late April 2012) + + asia + Changes for 2012 for Gaza & the West Bank (Hebron) and Syria + + northamerica + Haiti following US/Canada rules for 2012 (and we're assuming, + for now anyway, for the future). + + +Release 2012b - 2012-03-02 12:29:15 +0700 + + There is just one change to tzcode2012b (compared with 2012a): + the Makefile that was accidentally included with 2012a has been + replaced with the version that should have been there, which is + identical with the previous version (from tzcode2011i). + + There are just two changes in tzdata2012b compared with 2012a. + + Most significantly, summer time in Cuba has been delayed 3 weeks + (now starts April 1 rather than March 11). Since Mar 11 (the old start + date, as listed in 2012a) is just a little over a week away, this + change is urgent. + + Less importantly, an excess tab in one of the changes in zone.tab + in 2012a has been removed. + + +Release 2012a - 2012-03-01 18:28:10 +0700 + + The changes in tzcode2012a (compared to the previous version, 2011i) + are entirely to the README and tz-art.htm and tz-link.htm files, if + none of those concern you, you can ignore the code update. The changes + reflect the changed addresses for the mailing list and the code and + data distribution points & methods (and a link to DateTime::TimeZone::Tzfile + has been added to tz-link.htm). + + In tzdata2012a (compared to the previous release, which was 2011n) + the major changes are: + Chile 2011/2012 and 2012/2013 summer time date adjustments. + Falkland Islands onto permanent summer time (we're assuming for the + foreseeable future, though 2012 is all we're fairly certain of.) + Armenia has abolished Summer Time. + Tokelau jumped the International Date Line back last December + (just the same as their near neighbour, Samoa). + America/Creston is a new zone for a small area of British Columbia + There will be a leapsecond 2012-06-30 23:59:60 UTC. + + Other minor changes are: + Corrections to 1918 Canadian summer time end dates. + Updated URL for UK time zone history (in comments) + A few typos in Le Corre's list of free French place names (comments) + + +Release data2011n - 2011-10-30 14:57:54 +0700 + + There are three changes of note - most urgently, Cuba (America/Havana) + has extended summer time by two weeks, now to end on Nov 13, rather than + the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic + (Europe/Tiraspol) decided not to split from the rest of Moldova after + all, and consequently that zone has been removed (again) and reinstated + in the "backward" file as a link to Europe/Chisinau. And third, the + end date for Fiji's summer time this summer was moved forward from the + earlier planned Feb 26, to Jan 22. + + Apart from that, Moldova (MD) returns to a single entry in zone.tab + (and the incorrect syntax that was in the 2011m version of that file + is so fixed - it would have been fixed in a different way had this + change not happened - that's the "missing" sccs version id). + + +Release data2011m - 2011-10-24 21:42:16 +0700 + + In particular, the typos in comments in the data (2011-11-17 should have + been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that + Tim Parenti noted) have been fixed, and the change for Ukraine has been + made in all 4 Ukrainian zones, rather than just Europe/Kiev + (again, thanks to Tim Parenti, and also Denys Gavrysh). + + In addition, I added Europe/Tiraspol to zone.tab. + + This time, all the files have new version numbers... (including the files + otherwise unchanged in 2011m that were changed in 2011l but didn't get new + version numbers there...) + + +Release data2011l - 2011-10-10 11:15:43 +0700 + + There are just 2 changes that cause different generated tzdata files from + zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil + is included, but commented out. Compared with the diff I sent out last week, + this version also includes attributions for the sources for the changes + (in much the same format as ado used, but the html tags have not been + checked, verified, or used in any way at all, so if there are errors there, + please let me know.) + + +Release data2011k - 2011-09-20 17:54:03 -0400 + + [not summarized] + + +Release data2011j - 2011-09-12 09:22:49 -0400 + + (contemporary changes for Samoa; past changes for Kenya, Uganda, and + Tanzania); there are also two spelling corrections to comments in + the australasia file (with thanks to Christos Zoulas). + + +Release 2011i - 2011-08-29 05:56:32 -0400 + + [not summarized] + + +Release data2011h - 2011-06-15 18:41:48 -0400 + + Russia and Curaçao changes + + +Release 2011g - 2011-04-25 09:07:22 -0400 + + update the rules for Egypt to reflect its abandonment of DST this year + + +Release 2011f - 2011-04-06 17:14:53 -0400 + + [not summarized] + + +Release 2011e - 2011-03-31 16:04:38 -0400 + + Morocco, Chile, and tz-link changes + + +Release 2011d - 2011-03-14 09:18:01 -0400 + + changes that impact present-day timestamps in Cuba, Samoa, and Turkey + + +Release 2011c - 2011-03-07 09:30:09 -0500 + + These do affect current timestamps in Chile and Annette Island, Canada. + + +Release 2011b - 2011-02-07 08:44:50 -0500 + + [not summarized] + + +Release 2011a - 2011-01-24 10:30:16 -0500 + + [not summarized] + + +Release data2010o - 2010-11-01 09:18:23 -0400 + + change to the end of DST in Fiji in 2011 + + +Release 2010n - 2010-10-25 08:19:17 -0400 + + [not summarized] + + +Release 2010m - 2010-09-27 09:24:48 -0400 + + Hong Kong, Vostok, and zic.c changes + + +Release 2010l - 2010-08-16 06:57:25 -0400 + + [not summarized] + + +Release 2010k - 2010-07-26 10:42:27 -0400 + + [not summarized] + + +Release 2010j - 2010-05-10 09:07:48 -0400 + + changes for Bahía de Banderas and for version naming + + +Release data2010i - 2010-04-16 18:50:45 -0400 + + the end of DST in Morocco on 2010-08-08 + + +Release data2010h - 2010-04-05 09:58:56 -0400 + + [not summarized] + + +Release data2010g - 2010-03-24 11:14:53 -0400 + + [not summarized] + + +Release 2010f - 2010-03-22 09:45:46 -0400 + + [not summarized] + + +Release data2010e - 2010-03-08 14:24:27 -0500 + + corrects the Dhaka bug found by Danvin Ruangchan + + +Release data2010d - 2010-03-06 07:26:01 -0500 + + [not summarized] + + +Release 2010c - 2010-03-01 09:20:58 -0500 + + changes including KRE's suggestion for earlier initialization of + "goahead" and "goback" structure elements + + +Release code2010a - 2010-02-16 10:40:04 -0500 + + [not summarized] + + +Release data2010b - 2010-01-20 12:37:01 -0500 + + Mexico changes + + +Release data2010a - 2010-01-18 08:30:04 -0500 + + changes to Dhaka + + +Release data2009u - 2009-12-26 08:32:28 -0500 + + changes to DST in Bangladesh + + +Release 2009t - 2009-12-21 13:24:27 -0500 + + [not summarized] + + +Release data2009s - 2009-11-14 10:26:32 -0500 + + (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change + + +Release 2009r - 2009-11-09 10:10:31 -0500 + + "antarctica" and "tz-link.htm" changes + + +Release 2009q - 2009-11-02 09:12:40 -0500 + + with two corrections as reported by Eric Muller and Philip Newton + + +Release data2009p - 2009-10-23 15:05:27 -0400 + + Argentina (including San Luis) changes (with the correction from + Mariano Absatz) + + +Release data2009o - 2009-10-14 16:49:38 -0400 + + Samoa (commentary only), Pakistan, and Bangladesh changes + + +Release data2009n - 2009-09-22 15:13:38 -0400 + + added commentary for Argentina and a change to the end of DST in + 2009 in Pakistan + + +Release data2009m - 2009-09-03 10:23:43 -0400 + + Samoa and Palestine changes + + +Release data2009l - 2009-08-14 09:13:07 -0400 + + Samoa (comments only) and Egypt + + +Release 2009k - 2009-07-20 09:46:08 -0400 + + [not summarized] + + +Release data2009j - 2009-06-15 06:43:59 -0400 + + Bangladesh change (with a short turnaround since the DST change is + impending) + + +Release 2009i - 2009-06-08 09:21:22 -0400 + + updating for DST in Bangladesh this year + + +Release 2009h - 2009-05-26 09:19:14 -0400 + + [not summarized] + + +Release data2009g - 2009-04-20 16:34:07 -0400 + + Cairo + + +Release data2009f - 2009-04-10 11:00:52 -0400 + + correct DST in Pakistan + + +Release 2009e - 2009-04-06 09:08:11 -0400 + + [not summarized] + + +Release 2009d - 2009-03-23 09:38:12 -0400 + + Morocco, Tunisia, Argentina, and American Astronomical Society changes + + +Release data2009c - 2009-03-16 09:47:51 -0400 + + change to the start of Cuban DST + + +Release 2009b - 2009-02-09 11:15:22 -0500 + + [not summarized] + + +Release 2009a - 2009-01-21 10:09:39 -0500 + + [not summarized] + + +Release data2008i - 2008-10-21 12:10:25 -0400 + + southamerica and zone.tab files, with Argentina DST rule changes and + United States zone reordering and recommenting + + +Release 2008h - 2008-10-13 07:33:56 -0400 + + [not summarized] + + +Release 2008g - 2008-10-06 09:03:18 -0400 + + Fix a broken HTML anchor and update Brazil's DST transitions; + there's also a slight reordering of information in tz-art.htm. + + +Release data2008f - 2008-09-09 22:33:26 -0400 + + [not summarized] + + +Release 2008e - 2008-07-28 14:11:17 -0400 + + changes by Arthur David Olson and Jesper Nørgaard Welen + + +Release data2008d - 2008-07-07 09:51:38 -0400 + + changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo + + +Release data2008c - 2008-05-19 17:48:03 -0400 + + Pakistan, Morocco, and Mongolia + + +Release data2008b - 2008-03-24 08:30:59 -0400 + + including renaming Asia/Calcutta to Asia/Kolkata, with a backward + link provided + + +Release 2008a - 2008-03-08 05:42:16 -0500 + + [not summarized] + + +Release 2007k - 2007-12-31 10:25:22 -0500 + + most importantly, changes to the "southamerica" file based on + Argentina's readoption of daylight saving time + + +Release 2007j - 2007-12-03 09:51:01 -0500 + + 1. eliminate the "P" (parameter) macro; + + 2. the "noncontroversial" changes circulated on the time zone + mailing list (less the changes to "logwtmp.c"); + + 3. eliminate "too many transition" errors when "min" is used in time + zone rules; + + 4. changes by Paul Eggert (including updated information for Venezuela). + + +Release data2007i - 2007-10-30 10:28:11 -0400 + + changes for Cuba and Syria + + +Release 2007h - 2007-10-01 10:05:51 -0400 + + changes by Paul Eggert, as well as an updated link to the ICU + project in tz-link.htm + + +Release 2007g - 2007-08-20 10:47:59 -0400 + + changes by Paul Eggert + + The "leapseconds" file has been updated to incorporate the most + recent International Earth Rotation and Reference Systems Service + (IERS) bulletin. + + There's an addition to tz-art.htm regarding the television show "Medium". + + +Release 2007f - 2007-05-07 10:46:46 -0400 + + changes by Paul Eggert (including Haiti, Turks and Caicos, and New + Zealand) + + changes to zic.c to allow hour values greater than 24 (along with + Paul's improved time value overflow checking) + + +Release 2007e - 2007-04-02 10:11:52 -0400 + + Syria and Honduras changes by Paul Eggert + + zic.c variable renaming changes by Arthur David Olson + + +Release 2007d - 2007-03-20 08:48:30 -0400 + + changes by Paul Eggert + + the elimination of white space at the ends of lines + + +Release 2007c - 2007-02-26 09:09:37 -0500 + + changes by Paul Eggert + + +Release 2007b - 2007-02-12 09:34:20 -0500 + + Paul Eggert's proposed change to the quotation handling logic in zic.c. + + changes to the commentary in "leapseconds" reflecting the IERS + announcement that there is to be no positive leap second at the end + of June 2007. + + +Release 2007a - 2007-01-08 12:28:29 -0500 + + changes by Paul Eggert + + Derick Rethans's Asmara change + + Oscar van Vlijmen's Easter Island local mean time change + + symbolic link changes + + +Release 2006p - 2006-11-27 08:54:27 -0500 + + changes by Paul Eggert + + +Release 2006o - 2006-11-06 09:18:07 -0500 + + changes by Paul Eggert + + +Release 2006n - 2006-10-10 11:32:06 -0400 + + changes by Paul Eggert + + +Release 2006m - 2006-10-02 15:32:35 -0400 + + changes for Uruguay, Palestine, and Egypt by Paul Eggert + + (minimalist) changes to zic.8 to clarify "until" information + + +Release data2006l - 2006-09-18 12:58:11 -0400 + + Paul's best-effort work on this coming weekend's Egypt time change + + +Release 2006k - 2006-08-28 12:19:09 -0400 + + changes by Paul Eggert + + +Release 2006j - 2006-08-21 09:56:32 -0400 + + changes by Paul Eggert + + +Release code2006i - 2006-08-07 12:30:55 -0400 + + localtime.c fixes + + Ken Pizzini's conversion script + + +Release code2006h - 2006-07-24 09:19:37 -0400 + + adds public domain notices to four files + + includes a fix for transition times being off by a second + + adds a new recording to the "arts" file (information courtesy Colin Bowern) + + +Release 2006g - 2006-05-08 17:18:09 -0400 + + northamerica changes by Paul Eggert + + +Release 2006f - 2006-05-01 11:46:00 -0400 + + a missing version number problem is fixed (with thanks to Bradley + White for catching the problem) + + +Release 2006d - 2006-04-17 14:33:43 -0400 + + changes by Paul Eggert + + added new items to tz-arts.htm that were found by Paul + + +Release 2006c - 2006-04-03 10:09:32 -0400 + + two sets of data changes by Paul Eggert + + a fencepost error fix in zic.c + + changes to zic.c and the "europe" file to minimize differences + between output produced by the old 32-bit zic and the new 64-bit + version + + +Release 2006b - 2006-02-20 10:08:18 -0500 + [tz32code2006b + tz64code2006b + tzdata2006b] + + 64-bit code + + All SCCS IDs were bumped to "8.1" for this release. + + +Release 2006a - 2006-01-30 08:59:31 -0500 + + changes by Paul Eggert (in particular, Indiana time zone moves) + + an addition to the zic manual page to describe how special-case + transitions are handled + + +Release 2005r - 2005-12-27 09:27:13 -0500 + + Canadian changes by Paul Eggert + + They also add "<pre>" directives to time zone data files and reflect + changes to warning message logic in "zdump.c" (but with calls to + "gettext" kept unbundled at the suggestion of Ken Pizzini). + + +Release 2005q - 2005-12-13 09:17:09 -0500 + + Nothing earth-shaking here: + 1. Electronic mail addresses have been removed. + 2. Casts of the return value of exit have been removed. + 3. Casts of the argument of is.* macros have been added. + 4. Indentation in one section of zic.c has been fixed. + 5. References to dead URLs in the data files have been dealt with. + + +Release 2005p - 2005-12-05 10:30:53 -0500 + + "systemv", "tz-link.htm", and "zdump.c" changes + (less the casts of arguments to the is* macros) + + +Release 2005o - 2005-11-28 10:55:26 -0500 + + Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert + + zdump.c lint fixes by Arthur David Olson + + +Release 2005n - 2005-10-03 09:44:09 -0400 + + changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan + et al. changes) + + +Release 2005m - 2005-08-29 12:15:40 -0400 + + changes by Paul Eggert (with a small tweak to the tz-art change) + + a declaration of an unused variable has been removed from zdump.c + + +Release 2005l - 2005-08-22 12:06:39 -0400 + + changes by Paul Eggert + + overflow/underflow checks by Arthur David Olson, minus changes to + the "Theory" file about the pending addition of 64-bit data (I grow + less confident of the changes being accepted with each passing day, + and the changes no longer increase the data files nine-fold--there's + less than a doubling in size by my local Sun's reckoning) + + +Release 2005k - 2005-07-14 14:14:24 -0400 + + The "leapseconds" file has been edited to reflect the recently + announced leap second at the end of 2005. + + I've also deleted electronic mail addresses from the files as an + anti-spam measure. + + +Release 2005j - 2005-06-13 14:34:13 -0400 + + These reflect changes to limit the length of time zone abbreviations + and the characters used in those abbreviations. + + There are also changes to handle POSIX-style "quoted" timezone + environment variables. + + The changes were circulated on the time zone mailing list; the only + change since then was the removal of a couple of minimum-length of + abbreviation checks. + + +Release data2005i - 2005-04-21 15:04:16 -0400 + + changes (most importantly to Nicaragua and Haiti) by Paul Eggert + + +Release 2005h - 2005-04-04 11:24:47 -0400 + + changes by Paul Eggert + + minor changes to Makefile and zdump.c to produce more useful output + when doing a "make typecheck" + + +Release 2005g - 2005-03-14 10:11:21 -0500 + + changes by Paul Eggert (a change to current DST rules in Uruguay and + an update to a link to time zone software) + + +Release 2005f - 2005-03-01 08:45:32 -0500 + + data and documentation changes by Paul Eggert + + +Release 2005e - 2005-02-10 15:59:44 -0500 + + [not summarized] + + +Release code2005d - 2005-01-31 09:21:47 -0500 + + make zic complain about links to links if the -v flag is used + + have "make public" do more code checking + + add an include to "localtime.c" for the benefit of gcc systems + + +Release 2005c - 2005-01-17 18:36:29 -0500 + + get better results when mktime runs on a system where time_t is double + + changes to the data files (most importantly to Paraguay) + + +Release 2005b - 2005-01-10 09:19:54 -0500 + + Get localtime and gmtime working on systems with exotic time_t types. + + Update the leap second commentary in the "leapseconds" file. + + +Release 2005a - 2005-01-01 13:13:44 -0500 + + [not summarized] + + +Release code2004i - 2004-12-14 13:42:58 -0500 + + Deal with systems where time_t is unsigned. + + +Release code2004h - 2004-12-07 11:40:18 -0500 + + 64-bit-time_t changes + + +Release 2004g - 2004-11-02 09:06:01 -0500 + + update to Cuba (taking effect this weekend) + + other changes by Paul Eggert + + correction of the spelling of Oslo + + changed versions of difftime.c and private.h + + +Release code2004f - 2004-10-21 10:25:22 -0400 + + Cope with wide-ranging tm_year values. + + +Release 2004e - 2004-10-11 14:47:21 -0400 + + Brazil/Argentina/Israel changes by Paul Eggert + + changes to tz-link.htm by Paul + + one small fix to Makefile + + +Release 2004d - 2004-09-22 08:27:29 -0400 + + Avoid overflow problems when TM_YEAR_BASE is added to an integer. + + +Release 2004c - 2004-08-11 12:06:26 -0400 + + asctime-related changes + + (variants of) some of the documentation changes suggested by Paul Eggert + + +Release 2004b - 2004-07-19 14:33:35 -0400 + + data changes by Paul Eggert - most importantly, updates for Argentina + + +Release 2004a - 2004-05-27 12:00:47 -0400 + + changes by Paul Eggert + + Handle DST transitions that occur at the end of a month in some + years but at the start of the following month in other years. + + Add a copy of the correspondence that's the basis for claims about + DST in the Navajo Nation. + + +Release 2003e - 2003-12-15 09:36:47 -0500 + + changes by Arthur David Olson (primarily code changes) + + changes by Paul Eggert (primarily data changes) + + minor changes to "Makefile" and "northamerica" (in the latter case, + optimization of the "Toronto" rules) + + +Release 2003d - 2003-10-06 09:34:44 -0400 + + changes by Paul Eggert + + +Release 2003c - 2003-09-16 10:47:05 -0400 + + Fix bad returns in zic.c's inleap function. + Thanks to Bradley White for catching the problem! + + +Release 2003b - 2003-09-16 07:13:44 -0400 + + Add a "--version" option (and documentation) to the zic and zdump commands. + + changes to overflow/underflow checking in zic + + a localtime typo fix. + + Update the leapseconds and tz-art.htm files. + + +Release 2003a - 2003-03-24 09:30:54 -0500 + + changes by Paul Eggert + + a few additions and modifications to the tz-art.htm file + + +Release 2002d - 2002-10-15 13:12:42 -0400 + + changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab + + There's also a new time zone quote in "tz-art.htm". + + +Release 2002c - 2002-04-04 11:55:20 -0500 + + changes by Paul Eggert + + Change zic.c to avoid creating symlinks to files that don't exist. + + +Release 2002b - 2002-01-28 12:56:03 -0500 + + [These change notes are for Release 2002a, which was corrupted. + 2002b was a corrected version of 2002a.] + + changes by Paul Eggert + + Update the "leapseconds" file to note that there'll be no leap + second at the end of June, 2002. + + Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone. + + Change to "difftime.c" to avoid sizeof problems. + + +Release 2001d - 2001-10-09 13:31:32 -0400 + + changes by Paul Eggert + + +Release 2001c - 2001-06-05 13:59:55 -0400 + + changes by Paul Eggert and Andrew Brown + + +Release 2001b - 2001-04-05 16:44:38 -0400 + + changes by Paul Eggert (modulo jnorgard's typo fix) + + tz-art.htm has been HTMLified. + + +Release 2001a - 2001-03-13 12:57:44 -0500 + + changes by Paul Eggert + + An addition to the "leapseconds" file: comments with the text of the + latest IERS leap second notice. + + Trailing white space has been removed from data file lines, and + repeated spaces in "Rule Jordan" lines in the "asia" file have been + converted to tabs. + + +Release 2000h - 2000-12-14 15:33:38 -0500 + + changes by Paul Eggert + + one typo fix in the "art" file + + With providence, this is the last update of the millennium. + + +Release 2000g - 2000-10-10 11:35:22 -0400 + + changes by Paul Eggert + + correction of John Mackin's name submitted by Robert Elz + + Garry Shandling's Daylight Saving Time joke (!?!) from the recent + Emmy Awards broadcast. + + +Release 2000f - 2000-08-10 09:31:58 -0400 + + changes by Paul Eggert + + Added information in "tz-art.htm" on a Seinfeld reference to DST. + + Error checking and messages in the "yearistype" script have been + improved. + + +Release 2000e - 2000-07-31 09:27:54 -0400 + + data changes by Paul Eggert + + a change to the default value of the defined constant HAVE_STRERROR + + the addition of a Dave Barry quote on DST to the tz-arts file + + +Release 2000d - 2000-04-20 15:43:04 -0400 + + changes to the documentation and code of strftime for C99 conformance + + a bug fix for date.c + + These are based on (though modified from) changes by Paul Eggert. + + +Release 2000c - 2000-03-04 10:31:43 -0500 + + changes by Paul Eggert + + +Release 2000b - 2000-02-21 12:16:29 -0500 + + changes by Paul Eggert and Joseph Myers + + modest tweaks to the tz-art.htm and tz-link.htm files + + +Release 2000a - 2000-01-18 09:21:26 -0500 + + changes by Paul Eggert + + The two hypertext documents have also been renamed. + + +Release code1999i-data1999j - 1999-11-15 18:43:22 -0500 + + Paul Eggert's changes + + additions to the "zic" manual page and the "Arts.htm" file + + +Release code1999h-data1999i - 1999-11-08 14:55:21 -0500 + + [not summarized] + + +Release data1999h - 1999-10-07 03:50:29 -0400 + + changes by Paul Eggert to "europe" (most importantly, fixing + Lithuania and Estonia) + + +Release 1999g - 1999-09-28 11:06:18 -0400 + + data changes by Paul Eggert (most importantly, the change for + Lebanon that buys correctness for this coming Sunday) + + The "code" file contains changes to "Makefile" and "checktab.awk" to + allow better checking of time zone files before they are published. + + +Release 1999f - 1999-09-23 09:48:14 -0400 + + changes by Arthur David Olson and Paul Eggert + + +Release 1999e - 1999-08-17 15:20:54 -0400 + + changes circulated by Paul Eggert, although the change to handling + of DST-specifying timezone names has been commented out for now + (search for "XXX" in "localtime.c" for details). These files also + do not make any changes to the start of DST in Brazil. + + In addition to Paul's changes, there are updates to "Arts.htm" and + cleanups of URLs. + + +Release 1999d - 1999-03-30 11:31:07 -0500 + + changes by Paul Eggert + + The Makefile's "make public" rule has also been changed to do a test + compile of each individual time zone data file (which should help + avoid problems such as the one we had with Nicosia). + + +Release 1999c - 1999-03-25 09:47:47 -0500 + + changes by Paul Eggert, most importantly the change for Chile. + + +Release 1999b - 1999-02-01 17:51:44 -0500 + + changes by Paul Eggert + + code changes (suggested by Mani Varadarajan, mani at be.com) for + correct handling of symbolic links when building using a relative directory + + code changes to generate correct messages for failed links + + updates to the URLs in Arts.htm + + +Release 1999a - 1999-01-19 16:20:29 -0500 + + error message internationalizations and corrections in zic.c and + zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz, + to whom thanks!) + + +Release code1998h-data1998i - 1998-10-01 09:56:10 -0400 + + changes for Brazil, Chile, and Germany + + support for use of "24:00" in the input files for the time zone compiler + + +Release code1998g-data1998h - 1998-09-24 10:50:28 -0400 + + changes by Paul Eggert + + correction to a define in the "private.h" file + + +Release data1998g - 1998-08-11 03:28:35 -0000 + [tzdata1998g.tar.gz is missing!] + + Lithuanian change provided by mgedmin at pub.osf.it + + Move creation of the GMT link with Etc/GMT to "etcetera" (from + "backward") to ensure that the GMT file is created even where folks + don't want the "backward" links (as suggested by Paul Eggert). + + +Release data1998f - 1998-07-20 13:50:00 -0000 + [tzdata1998f.tar.gz is missing!] + + Update the "leapseconds" file to include the newly announced + insertion at the end of 1998. + + +Release code1998f - 1998-06-01 10:18:31 -0400 + + addition to localtime.c by Guy Harris + + +Release 1998e - 1998-05-28 09:56:26 -0400 + + The Makefile is changed to produce zoneinfo-posix rather than + zoneinfo/posix, and to produce zoneinfo-leaps rather than + zoneinfo/right. + + data changes by Paul Eggert + + changes from Guy Harris to provide asctime_r and ctime_r + + A usno1998 file (substantially identical to usno1997) has been added. + + +Release 1998d - 1998-05-14 11:58:34 -0400 + + changes to comments (in particular, elimination of references to CIA maps). + "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places + where changes occur. + + +Release 1998c - 1998-02-28 12:32:26 -0500 + + changes by Paul Eggert (save the "French correction," on which I'll + wait for the dust to settle) + + symlink changes + + changes and additions to Arts.htm + + +Release 1998b - 1998-01-17 14:31:51 -0500 + + URL cleanups and additions + + +Release 1998a - 1998-01-13 12:37:35 -0500 + + changes by Paul Eggert + + +Release code1997i-data1997k - 1997-12-29 09:53:41 -0500 + + changes by Paul Eggert, with minor modifications from Arthur David + Olson to make the files more browser friendly + + +Release code1997h-data1997j - 1997-12-18 17:47:35 -0500 + + minor changes to put "TZif" at the start of each timezone information file + + a rule has also been added to the Makefile so you can + make zones + to just recompile the zone information files (rather than doing a + full "make install" with its other effects). + + +Release data1997i - 1997-10-07 08:45:38 -0400 + + changes to Africa by Paul Eggert + + +Release code1997g-data1997h - 1997-09-04 16:56:54 -0400 + + corrections for Uruguay (and other locations) + + Arthur David Olson's simple-minded fix allowing mktime to both + correctly handle leap seconds and correctly handle tm_sec values + upon which arithmetic has been performed. + + +Release code1997f-data1997g - 1997-07-19 13:15:02 -0400 + + Paul Eggert's updates + + a small change to a function prototype; + + "Music" has been renamed "Arts.htm", HTMLified, and augmented to + include information on Around the World in Eighty Days. + + +Release code1997e-data1997f - 1997-05-03 18:52:34 -0400 + + fixes to zic's error handling + + changes inspired by the item circulated on Slovenia + + The description of Web resources has been HTMLified for browsing + convenience. + + A new piece of tz-related music has been added to the "Music" file. + + +Release code1997d-data1997e - 1997-03-29 12:48:52 -0500 + + Paul Eggert's latest suggestions + + +Release code1997c-data1997d - 1997-03-07 20:37:54 -0500 + + changes to "zic.c" to correct performance of the "-s" option + + a new file "usno1997" + + +Release data1997c - 1997-03-04 09:58:18 -0500 + + changes in Israel + + +Release 1997b - 1997-02-27 18:34:19 -0500 + + The data file incorporates the 1997 leap second. + + The code file incorporates Arthur David Olson's take on the + zic/multiprocessor/directory-creation situation. + + +Release 1997a - 1997-01-21 09:11:10 -0500 + + Paul Eggert's Antarctica (and other changes) + + Arthur David Olson finessed the "getopt" issue by checking against + both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1 + is returned while SunOS 5.5's manual says EOF is returned). + + +Release code1996o-data1996n - 1996-12-27 21:42:05 -0500 + + Paul Eggert's latest changes + + +Release code1996n - 1996-12-16 09:42:02 -0500 + + link snapping fix from Bruce Evans (via Garrett Wollman) + + +Release data1996m - 1996-11-24 02:37:34 -0000 + [tzdata1996m.tar.gz is missing!] + + Paul Eggert's batch of changes + + +Release code1996m-data1996l - 1996-11-05 14:00:12 -0500 + + No functional changes here; the files have simply been changed to + make more use of ISO style dates in comments. The names of the above + files now include the year in full. + + +Release code96l - 1996-09-08 17:12:20 -0400 + + tzcode96k was missing a couple of pieces. + + +Release 96k - 1996-09-08 16:06:22 -0400 + + the latest round of changes from Paul Eggert + + the recent Year 2000 material + + +Release code96j - 1996-07-30 13:18:53 -0400 + + Set sp->typecnt as suggested by Timothy Patrick Murphy. + + +Release code96i - 1996-07-27 20:11:35 -0400 + + Paul's suggested patch for strftime %V week numbers + + +Release data96i - 1996-07-01 18:13:04 -0400 + + "northamerica" and "europe" changes by Paul Eggert + + +Release code96h - 1996-06-05 08:02:21 -0400 + + fix for handling transitions specified in Universal Time + + Some "public domain" notices have also been added. + + +Release code96g - 1996-05-16 14:00:26 -0400 + + fix for the simultaneous-DST-and-zone-change challenge + + +Release data96h - 1996-05-09 17:40:51 -0400 + + changes by Paul Eggert + + +Release code96f-data96g - 1996-05-03 03:09:59 -0000 + [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!] + + The changes get us some of the way to fixing the problems noted in Paul + Eggert's letter yesterday (in addition to a few others). The approach + has been to make zic a bit smarter about figuring out what time zone + abbreviations apply just after the time specified in the "UNTIL" part + of a zone line. Putting the smarts in zic means avoiding having + transition times show up in both "Zone" lines and "Rule" lines, which + in turn avoids multiple transition time entries in time zone files. + (This also makes the zic input files such as "europe" a bit shorter and + should ease maintenance.) + + +Release data96f - 1996-04-19 19:20:03 -0000 + [tzdata96f.tar.gz is missing!] + + The only changes are to the "northamerica" file; the time zone + abbreviation for Denver is corrected to MST (and MDT), and the + comments for Mexico have been updated. + + +Release data96e - 1996-03-19 17:37:26 -0500 + + Proposals by Paul Eggert, in particular the Portugal change that + comes into play at the end of this month. + + +Release data96d - 1996-03-18 20:49:39 -0500 + + [not summarized] + + +Release code96e - 1996-02-29 15:43:27 -0000 + [tzcode96e.tar.gz is missing!] + + internationalization changes and the fix to the documentation for strftime + + +Release code96d-data96c - 1996-02-12 11:05:27 -0500 + + The "code" file simply updates Bob Kridle's electronic address. + + The "data" file updates rules for Mexico. + + +Release data96b - 1996-01-27 15:44:42 -0500 + + Kiribati change + + +Release code96c - 1996-01-16 16:58:15 -0500 + + leap-year streamlining and binary-search changes + + fix to newctime.3 + + +Release code96b - 1996-01-10 20:42:39 -0500 + + fixes and enhancements from Paul Eggert, including code that + emulates the behavior of recent versions of the SunOS "date" + command. + + +Release 96a - 1996-01-06 09:08:24 -0500 + + Israel updates + + fixes to strftime.c for correct ISO 8601 week number generation, + plus support for two new formats ('G' and 'g') to give ISO 8601 year + numbers (which are not necessarily the same as calendar year numbers) + + +Release code95i-data95m - 1995-12-21 12:46:47 -0500 + + The latest revisions from Paul Eggert are included, the usno1995 + file has been updated, and a new file ("WWW") covering useful URLs + has been added. + + +Release code95h-data95l - 1995-12-19 18:10:12 -0500 + + A simplification of a macro definition, a change to data for Sudan, + and (for last minute shoppers) notes in the "Music" file on the CD + "Old Man Time". + + +Release code95g-data95k - 1995-10-30 10:32:47 -0500 + + (slightly reformatted) 8-bit-clean proposed patch + + minor patch: US/Eastern -> America/New_York + + snapshot of the USNO's latest data ("usno1995") + + some other minor cleanups + + +Release code95f-data95j - 1995-10-28 21:01:34 -0000 + [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!] + + European cleanups + + support for 64-bit time_t's + + optimization in localtime.c + + +Release code95e - 1995-10-13 13:23:57 -0400 + + the mktime change to scan from future to past when trying to find time zone + offsets + + +Release data95i - 1995-09-26 10:43:26 -0400 + + For Canada/Central, guess that the Sun customer's "one week too + early" was just a approximation, and the true error is one month + too early. This is consistent with the rest of Canada. + + +Release data95h - 1995-09-21 11:26:48 -0400 + + latest changes from Paul Eggert + + +Release code95d - 1995-09-14 11:14:45 -0400 + + the addition of a "Music" file, which documents four recorded + versions of the tune "Save That Time". + + +Release data95g - 1995-09-01 17:21:36 -0400 + + "yearistype" correction + + +Release data95f - 1995-08-28 20:46:56 -0400 + + Paul Eggert's change to the australasia file + + +Release data95e - 1995-07-08 18:02:34 -0400 + + The only change is a leap second at the end of this year. + Thanks to Bradley White for forwarding news on the leap second. + + +Release data95d - 1995-07-03 13:26:22 -0400 + + Paul Eggert's changes + + +Release data95c - 1995-07-02 19:19:28 -0400 + + changes to "asia", "backward", "europe", and "southamerica" + (read: northamericacentrics need not apply) + + +Release code95c - 1995-03-13 14:00:46 -0500 + + one-line fix for sign extension problems in detzcode + + +Release 95b - 1995-03-04 11:22:38 -0500 + + Minor changes in both: + + The "code" file contains a workaround for the lack of "unistd.h" in + Microsoft C++ version 7. + + The "data" file contains a fixed "Link" for America/Shiprock. + + +Release 94h - 1994-12-10 12:51:14 -0500 + + The files: + + * incorporate the changes to "zdump" and "date" to make changes to + the "TZ" environment variable permanent; + + * incorporate the table changes by Paul Eggert; + + * include (and document) support for universal time specifications in + data files - but do not (yet) include use of this feature in the + data files. + + Think of this as "TZ Classic" - the software has been set up not to break if + universal time shows up in its input, and data entries have been + left as is so as not to break existing implementations. + + +Release data94f - 1994-08-20 12:56:09 -0400 + + (with thanks!) the latest data updates from Paul Eggert + + +Release data94e - 1994-06-04 13:13:53 -0400 + + [not summarized] + + +Release code94g - 1994-05-05 12:14:07 -0400 + + fix missing "optind.c" and a reference to it in the Makefile + + +Release code94f - 1994-05-05 13:00:33 -0000 + [tzcode94f.tar.gz is missing!] + + changes to avoid overflow in difftime, as well as changes to cope + with the 52/53 challenge in strftime + + +Release code94e - 1994-03-30 23:32:59 -0500 + + change for the benefit of PCTS + + +Release 94d - 1994-02-24 15:42:25 -0500 + + Avoid clashes with POSIX semantics for zones such as GMT+4. + + Some other very minor housekeeping is also present. + + +Release code94c - 1994-02-10 08:52:40 -0500 + + Fix bug where mkdirs was broken unless you compile with + -fwritable-strings (which is generally losing to do). + + +Release 94b - 1994-02-07 10:04:33 -0500 + + work by Paul Eggert who notes: + + I found another book of time zone histories by E W Whitman; it's not + as extensive as Shanks but has a few goodies of its own. I used it + to update the tables. I also fixed some more as a result of + correspondence with Adam David and Peter Ilieve, and move some stray + links from 'europe' to 'backward'. I corrected some scanning errors + in usno1989. + + As far as the code goes, I fixed zic to allow years in the range + INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900. + And I cleaned up the zic documentation a little bit. + + +Release data94a - 1994-02-03 08:58:54 -0500 + + It simply incorporates the recently announced leap second into the + "leapseconds" file. + + +Release 93g - 1993-11-22 17:28:27 -0500 + + Paul Eggert has provided a good deal of historic information (based + on Shanks), and there are some code changes to deal with the buglets + that crawled out in dealing with the new information. + + +Release 93f - 1993-10-15 12:27:46 -0400 + + Paul Eggert's changes + + +Release 93e - 1993-09-05 21:21:44 -0400 + + This has updated data for Israel, England, and Kwajalein. There's + also an update to "zdump" to cope with Kwajalein's 24-hour jump. + Thanks to Paul Eggert and Peter Ilieve for the changes. + + +Release 93d - 1993-06-17 23:34:17 -0400 + + new fix and new data on Israel + + +Release 93c - 1993-06-06 19:31:55 -0400 + + [not summarized] + + +Release 93b - 1993-02-02 14:53:58 -0500 + + updated "leapseconds" file + + +Release 93 - 1993-01-08 07:01:06 -0500 + + At kre's suggestion, the package has been split in two - a code piece + (which also includes documentation) that's only of use to folks who + want to recompile things and a data piece useful to anyone who can + run "zic". + + The new version has a few changes to the data files, a few + portability changes, and an off-by-one fix (with thanks to + Tom Karzes at deshaw.com for providing a description and a + solution). + + +Release 92c - 1992-11-21 17:35:36 -0000 + [tz92c.tar.Z is missing!] + + The fallout from the latest round of DST transitions. + + There are changes for Portugal, Saskatchewan, and "Pacific-New"; + there's also a change to "zic.c" that makes it portable to more systems. + + +Release 92 - 1992-04-25 18:17:03 -0000 + [tz92.tar.Z is missing!] + + By popular demand (well, at any rate, following a request by kre at munnari) + + +The 1989 update of the time zone package featured: + + * POSIXization (including interpretation of POSIX-style TZ environment + variables, provided by Guy Harris), + * ANSIfication (including versions of "mktime" and "difftime"), + * SVIDulation (an "altzone" variable) + * MACHination (the "gtime" function) + * corrections to some time zone data (including corrections to the rules + for Great Britain and New Zealand) + * reference data from the United States Naval Observatory for folks who + want to do additional time zones + * and the 1989 data for Saudi Arabia. + + (Since this code will be treated as "part of the implementation" in some + places and as "part of the application" in others, there's no good way to + name functions, such as timegm, that are not part of the proposed ANSI C + standard; such functions have kept their old, underscore-free names in this + update.) + + And the "dysize" function has disappeared; it was present to allow + compilation of the "date" command on old BSD systems, and a version of "date" + is now provided in the package. The "date" command is not created when you + "make all" since it may lack options provided by the version distributed with + your operating system, or may not interact with the system in the same way + the native version does. + + Since POSIX frowns on correct leap second handling, the default behavior of + the "zic" command (in the absence of a "-L" option) has been changed to omit + leap second information from its output files. + + +----- +Notes + +This file contains copies of the part of each release announcement +that talks about the changes in that release. The text has been +adapted and reformatted for the purposes of this file. + +Traditionally a release R consists of a pair of tarball files, +tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g., +code2010a, data2012c) consist of just one or the other tarball, and a +few (e.g., code2012c-data2012d) have tarballs with mixed version +numbers. Recent releases also come in an experimental format +consisting of a single tarball tzdb-R.tar.lz with extra data. + +Release timestamps are taken from the release's commit (for newer, +Git-based releases), from the newest file in the tarball (for older +releases, where this info is available) or from the email announcing +the release (if all else fails; these are marked with a time zone +abbreviation of -0000 and an "is missing!" comment). + +Earlier versions of the code and data were not announced on the tz +list and are not summarized here. + +This file is in the public domain. + +Local Variables: +coding: utf-8 +End: |