summaryrefslogtreecommitdiffstats
path: root/gitweb/static/js/lib/datetime.js
blob: f78c60a9125f0780611b9a3aae34970716cffc22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
// Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
//               2007, Petr Baudis <pasky@suse.cz>
//          2008-2011, Jakub Narebski <jnareb@gmail.com>

/**
 * @fileOverview Datetime manipulation: parsing and formatting
 * @license GPLv2 or later
 */


/* ............................................................ */
/* parsing and retrieving datetime related information */

/**
 * used to extract hours and minutes from timezone info, e.g '-0900'
 * @constant
 */
var tzRe = /^([+\-])([0-9][0-9])([0-9][0-9])$/;

/**
 * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
 *
 * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
 * @returns {Number} offset from UTC in seconds for timezone
 *
 * @globals tzRe
 */
function timezoneOffset(timezoneInfo) {
	var match = tzRe.exec(timezoneInfo);
	var tz_sign = (match[1] === '-' ? -1 : +1);
	var tz_hour = parseInt(match[2],10);
	var tz_min  = parseInt(match[3],10);

	return tz_sign*(((tz_hour*60) + tz_min)*60);
}

/**
 * return local (browser) timezone as offset from UTC in seconds
 *
 * @returns {Number} offset from UTC in seconds for local timezone
 */
function localTimezoneOffset() {
	// getTimezoneOffset returns the time-zone offset from UTC,
	// in _minutes_, for the current locale
	return ((new Date()).getTimezoneOffset() * -60);
}

/**
 * return local (browser) timezone as numeric timezone '(+|-)HHMM'
 *
 * @returns {String} locat timezone as -/+ZZZZ
 */
function localTimezoneInfo() {
	var tzOffsetMinutes = (new Date()).getTimezoneOffset() * -1;

	return formatTimezoneInfo(0, tzOffsetMinutes);
}


/**
 * Parse RFC-2822 date into a Unix timestamp (into epoch)
 *
 * @param {String} date: date in RFC-2822 format, e.g. 'Thu, 21 Dec 2000 16:01:07 +0200'
 * @returns {Number} epoch i.e. seconds since '00:00:00 1970-01-01 UTC'
 */
function parseRFC2822Date(date) {
	// Date.parse accepts the IETF standard (RFC 1123 Section 5.2.14 and elsewhere)
	// date syntax, which is defined in RFC 2822 (obsoletes RFC 822)
	// and returns number of _milli_seconds since January 1, 1970, 00:00:00 UTC
	return Date.parse(date) / 1000;
}


/* ............................................................ */
/* formatting date */

/**
 * format timezone offset as numerical timezone '(+|-)HHMM' or '(+|-)HH:MM'
 *
 * @param {Number} hours:    offset in hours, e.g. 2 for '+0200'
 * @param {Number} [minutes] offset in minutes, e.g. 30 for '-4030';
 *                           it is split into hours if not 0 <= minutes < 60,
 *                           for example 1200 would give '+0100';
 *                           defaults to 0
 * @param {String} [sep] separator between hours and minutes part,
 *                       default is '', might be ':' for W3CDTF (rfc-3339)
 * @returns {String} timezone in '(+|-)HHMM' or '(+|-)HH:MM' format
 */
function formatTimezoneInfo(hours, minutes, sep) {
	minutes = minutes || 0; // to be able to use formatTimezoneInfo(hh)
	sep = sep || ''; // default format is +/-ZZZZ

	if (minutes < 0 || minutes > 59) {
		hours = minutes > 0 ? Math.floor(minutes / 60) : Math.ceil(minutes / 60);
		minutes = Math.abs(minutes - 60*hours); // sign of minutes is sign of hours
		// NOTE: this works correctly because there is no UTC-00:30 timezone
	}

	var tzSign = hours >= 0 ? '+' : '-';
	if (hours < 0) {
		hours = -hours; // sign is stored in tzSign
	}

	return tzSign + padLeft(hours, 2, '0') + sep + padLeft(minutes, 2, '0');
}

/**
 * translate 'utc' and 'local' to numerical timezone
 * @param {String} timezoneInfo: might be 'utc' or 'local' (browser)
 */
function normalizeTimezoneInfo(timezoneInfo) {
	switch (timezoneInfo) {
	case 'utc':
		return '+0000';
	case 'local': // 'local' is browser timezone
		return localTimezoneInfo();
	}
	return timezoneInfo;
}


/**
 * return date in local time formatted in iso-8601 like format
 * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
 *
 * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
 * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
 * @returns {String} date in local time in iso-8601 like format
 */
function formatDateISOLocal(epoch, timezoneInfo) {
	// date corrected by timezone
	var localDate = new Date(1000 * (epoch +
		timezoneOffset(timezoneInfo)));
	var localDateStr = // e.g. '2005-08-07'
		localDate.getUTCFullYear()                 + '-' +
		padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
		padLeft(localDate.getUTCDate(),    2, '0');
	var localTimeStr = // e.g. '21:49:46'
		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
		padLeft(localDate.getUTCSeconds(), 2, '0');

	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
}

/**
 * return date in local time formatted in rfc-2822 format
 * e.g. 'Thu, 21 Dec 2000 16:01:07 +0200'
 *
 * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
 * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
 * @param {Boolean} [padDay] e.g. 'Sun, 07 Aug' if true, 'Sun, 7 Aug' otherwise
 * @returns {String} date in local time in rfc-2822 format
 */
function formatDateRFC2882(epoch, timezoneInfo, padDay) {
	// A short textual representation of a month, three letters
	var months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
	// A textual representation of a day, three letters
	var days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
	// date corrected by timezone
	var localDate = new Date(1000 * (epoch +
		timezoneOffset(timezoneInfo)));
	var localDateStr = // e.g. 'Sun, 7 Aug 2005' or 'Sun, 07 Aug 2005'
		days[localDate.getUTCDay()] + ', ' +
		(padDay ? padLeft(localDate.getUTCDate(),2,'0') : localDate.getUTCDate()) + ' ' +
		months[localDate.getUTCMonth()] + ' ' +
		localDate.getUTCFullYear();
	var localTimeStr = // e.g. '21:49:46'
		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
		padLeft(localDate.getUTCSeconds(), 2, '0');

	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
}

/* end of datetime.js */