summaryrefslogtreecommitdiffstats
path: root/vendor/chrono/src/lib.rs
blob: 861ee10593455f97b8ac069d58134aab6a3d1a42 (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
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
//! # Chrono: Date and Time for Rust
//!
//! It aims to be a feature-complete superset of
//! the [time](https://github.com/rust-lang-deprecated/time) library.
//! In particular,
//!
//! * Chrono strictly adheres to ISO 8601.
//! * Chrono is timezone-aware by default, with separate timezone-naive types.
//! * Chrono is space-optimal and (while not being the primary goal) reasonably efficient.
//!
//! There were several previous attempts to bring a good date and time library to Rust,
//! which Chrono builds upon and should acknowledge:
//!
//! * [Initial research on
//!    the wiki](https://github.com/rust-lang/rust-wiki-backup/blob/master/Lib-datetime.md)
//! * Dietrich Epp's [datetime-rs](https://github.com/depp/datetime-rs)
//! * Luis de Bethencourt's [rust-datetime](https://github.com/luisbg/rust-datetime)
//!
//! ### Features
//!
//! Chrono supports various runtime environments and operating systems, and has
//! several features that may be enabled or disabled.
//!
//! Default features:
//!
//! - `alloc`: Enable features that depend on allocation (primarily string formatting)
//! - `std`: Enables functionality that depends on the standard library. This
//!   is a superset of `alloc` and adds interoperation with standard library types
//!   and traits.
//! - `clock`: Enables reading the system time (`now`) that depends on the standard library for
//! UNIX-like operating systems and the Windows API (`winapi`) for Windows.
//!
//! Optional features:
//!
//! - [`serde`][]: Enable serialization/deserialization via serde.
//! - `unstable-locales`: Enable localization. This adds various methods with a
//!   `_localized` suffix. The implementation and API may change or even be
//!   removed in a patch release. Feedback welcome.
//!
//! [`serde`]: https://github.com/serde-rs/serde
//! [wasm-bindgen]: https://github.com/rustwasm/wasm-bindgen
//!
//! See the [cargo docs][] for examples of specifying features.
//!
//! [cargo docs]: https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#choosing-features
//!
//! ## Overview
//!
//! ### Duration
//!
//! Chrono currently uses its own [`Duration`] type to represent the magnitude
//! of a time span. Since this has the same name as the newer, standard type for
//! duration, the reference will refer this type as `OldDuration`.
//!
//! Note that this is an "accurate" duration represented as seconds and
//! nanoseconds and does not represent "nominal" components such as days or
//! months.
//!
//! When the `oldtime` feature is enabled, [`Duration`] is an alias for the
//! [`time::Duration`](https://docs.rs/time/0.1.40/time/struct.Duration.html)
//! type from v0.1 of the time crate. time v0.1 is deprecated, so new code
//! should disable the `oldtime` feature and use the `chrono::Duration` type
//! instead. The `oldtime` feature is enabled by default for backwards
//! compatibility, but future versions of Chrono are likely to remove the
//! feature entirely.
//!
//! Chrono does not yet natively support
//! the standard [`Duration`](https://doc.rust-lang.org/std/time/struct.Duration.html) type,
//! but it will be supported in the future.
//! Meanwhile you can convert between two types with
//! [`Duration::from_std`](https://docs.rs/time/0.1.40/time/struct.Duration.html#method.from_std)
//! and
//! [`Duration::to_std`](https://docs.rs/time/0.1.40/time/struct.Duration.html#method.to_std)
//! methods.
//!
//! ### Date and Time
//!
//! Chrono provides a
//! [**`DateTime`**](./struct.DateTime.html)
//! type to represent a date and a time in a timezone.
//!
//! For more abstract moment-in-time tracking such as internal timekeeping
//! that is unconcerned with timezones, consider
//! [`time::SystemTime`](https://doc.rust-lang.org/std/time/struct.SystemTime.html),
//! which tracks your system clock, or
//! [`time::Instant`](https://doc.rust-lang.org/std/time/struct.Instant.html), which
//! is an opaque but monotonically-increasing representation of a moment in time.
//!
//! `DateTime` is timezone-aware and must be constructed from
//! the [**`TimeZone`**](./offset/trait.TimeZone.html) object,
//! which defines how the local date is converted to and back from the UTC date.
//! There are three well-known `TimeZone` implementations:
//!
//! * [**`Utc`**](./offset/struct.Utc.html) specifies the UTC time zone. It is most efficient.
//!
//! * [**`Local`**](./offset/struct.Local.html) specifies the system local time zone.
//!
//! * [**`FixedOffset`**](./offset/struct.FixedOffset.html) specifies
//!   an arbitrary, fixed time zone such as UTC+09:00 or UTC-10:30.
//!   This often results from the parsed textual date and time.
//!   Since it stores the most information and does not depend on the system environment,
//!   you would want to normalize other `TimeZone`s into this type.
//!
//! `DateTime`s with different `TimeZone` types are distinct and do not mix,
//! but can be converted to each other using
//! the [`DateTime::with_timezone`](./struct.DateTime.html#method.with_timezone) method.
//!
//! You can get the current date and time in the UTC time zone
//! ([`Utc::now()`](./offset/struct.Utc.html#method.now))
//! or in the local time zone
//! ([`Local::now()`](./offset/struct.Local.html#method.now)).
//!
//! ```rust
//! use chrono::prelude::*;
//!
//! let utc: DateTime<Utc> = Utc::now();       // e.g. `2014-11-28T12:45:59.324310806Z`
//! let local: DateTime<Local> = Local::now(); // e.g. `2014-11-28T21:45:59.324310806+09:00`
//! # let _ = utc; let _ = local;
//! ```
//!
//! Alternatively, you can create your own date and time.
//! This is a bit verbose due to Rust's lack of function and method overloading,
//! but in turn we get a rich combination of initialization methods.
//!
//! ```rust
//! use chrono::prelude::*;
//! use chrono::offset::LocalResult;
//!
//! let dt = Utc.with_ymd_and_hms(2014, 7, 8, 9, 10, 11).unwrap(); // `2014-07-08T09:10:11Z`
//! // July 8 is 188th day of the year 2014 (`o` for "ordinal")
//! assert_eq!(dt, Utc.yo(2014, 189).and_hms_opt(9, 10, 11).unwrap());
//! // July 8 is Tuesday in ISO week 28 of the year 2014.
//! assert_eq!(dt, Utc.isoywd(2014, 28, Weekday::Tue).and_hms_opt(9, 10, 11).unwrap());
//!
//! let dt = NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_milli_opt(9, 10, 11, 12).unwrap().and_local_timezone(Utc).unwrap(); // `2014-07-08T09:10:11.012Z`
//! assert_eq!(dt, NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_micro_opt(9, 10, 11, 12_000).unwrap().and_local_timezone(Utc).unwrap());
//! assert_eq!(dt, NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_nano_opt(9, 10, 11, 12_000_000).unwrap().and_local_timezone(Utc).unwrap());
//!
//! // dynamic verification
//! assert_eq!(Utc.ymd_opt(2014, 7, 8).and_hms_opt(21, 15, 33),
//!            LocalResult::Single(Utc.with_ymd_and_hms(2014, 7, 8, 21, 15, 33).unwrap()));
//! assert_eq!(Utc.ymd_opt(2014, 7, 8).and_hms_opt(80, 15, 33), LocalResult::None);
//! assert_eq!(Utc.ymd_opt(2014, 7, 38).and_hms_opt(21, 15, 33), LocalResult::None);
//!
//! // other time zone objects can be used to construct a local datetime.
//! // obviously, `local_dt` is normally different from `dt`, but `fixed_dt` should be identical.
//! let local_dt = Local.from_local_datetime(&NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_milli_opt(9, 10, 11, 12).unwrap()).unwrap();
//! let fixed_dt = FixedOffset::east_opt(9 * 3600).unwrap().from_local_datetime(&NaiveDate::from_ymd_opt(2014, 7, 8).unwrap().and_hms_milli_opt(18, 10, 11, 12).unwrap()).unwrap();
//! assert_eq!(dt, fixed_dt);
//! # let _ = local_dt;
//! ```
//!
//! Various properties are available to the date and time, and can be altered individually.
//! Most of them are defined in the traits [`Datelike`](./trait.Datelike.html) and
//! [`Timelike`](./trait.Timelike.html) which you should `use` before.
//! Addition and subtraction is also supported.
//! The following illustrates most supported operations to the date and time:
//!
//! ```rust
//! use chrono::prelude::*;
//! use chrono::Duration;
//!
//! // assume this returned `2014-11-28T21:45:59.324310806+09:00`:
//! let dt = FixedOffset::east_opt(9*3600).unwrap().from_local_datetime(&NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_nano_opt(21, 45, 59, 324310806).unwrap()).unwrap();
//!
//! // property accessors
//! assert_eq!((dt.year(), dt.month(), dt.day()), (2014, 11, 28));
//! assert_eq!((dt.month0(), dt.day0()), (10, 27)); // for unfortunate souls
//! assert_eq!((dt.hour(), dt.minute(), dt.second()), (21, 45, 59));
//! assert_eq!(dt.weekday(), Weekday::Fri);
//! assert_eq!(dt.weekday().number_from_monday(), 5); // Mon=1, ..., Sun=7
//! assert_eq!(dt.ordinal(), 332); // the day of year
//! assert_eq!(dt.num_days_from_ce(), 735565); // the number of days from and including Jan 1, 1
//!
//! // time zone accessor and manipulation
//! assert_eq!(dt.offset().fix().local_minus_utc(), 9 * 3600);
//! assert_eq!(dt.timezone(), FixedOffset::east_opt(9 * 3600).unwrap());
//! assert_eq!(dt.with_timezone(&Utc), NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_nano_opt(12, 45, 59, 324310806).unwrap().and_local_timezone(Utc).unwrap());
//!
//! // a sample of property manipulations (validates dynamically)
//! assert_eq!(dt.with_day(29).unwrap().weekday(), Weekday::Sat); // 2014-11-29 is Saturday
//! assert_eq!(dt.with_day(32), None);
//! assert_eq!(dt.with_year(-300).unwrap().num_days_from_ce(), -109606); // November 29, 301 BCE
//!
//! // arithmetic operations
//! let dt1 = Utc.with_ymd_and_hms(2014, 11, 14, 8, 9, 10).unwrap();
//! let dt2 = Utc.with_ymd_and_hms(2014, 11, 14, 10, 9, 8).unwrap();
//! assert_eq!(dt1.signed_duration_since(dt2), Duration::seconds(-2 * 3600 + 2));
//! assert_eq!(dt2.signed_duration_since(dt1), Duration::seconds(2 * 3600 - 2));
//! assert_eq!(Utc.with_ymd_and_hms(1970, 1, 1, 0, 0, 0).unwrap() + Duration::seconds(1_000_000_000),
//!            Utc.with_ymd_and_hms(2001, 9, 9, 1, 46, 40).unwrap());
//! assert_eq!(Utc.with_ymd_and_hms(1970, 1, 1, 0, 0, 0).unwrap() - Duration::seconds(1_000_000_000),
//!            Utc.with_ymd_and_hms(1938, 4, 24, 22, 13, 20).unwrap());
//! ```
//!
//! ### Formatting and Parsing
//!
//! Formatting is done via the [`format`](./struct.DateTime.html#method.format) method,
//! which format is equivalent to the familiar `strftime` format.
//!
//! See [`format::strftime`](./format/strftime/index.html#specifiers)
//! documentation for full syntax and list of specifiers.
//!
//! The default `to_string` method and `{:?}` specifier also give a reasonable representation.
//! Chrono also provides [`to_rfc2822`](./struct.DateTime.html#method.to_rfc2822) and
//! [`to_rfc3339`](./struct.DateTime.html#method.to_rfc3339) methods
//! for well-known formats.
//!
//! Chrono now also provides date formatting in almost any language without the
//! help of an additional C library. This functionality is under the feature
//! `unstable-locales`:
//!
//! ```toml
//! chrono = { version = "0.4", features = ["unstable-locales"] }
//! ```
//!
//! The `unstable-locales` feature requires and implies at least the `alloc` feature.
//!
//! ```rust
//! use chrono::prelude::*;
//!
//! # #[cfg(feature = "unstable-locales")]
//! # fn test() {
//! let dt = Utc.with_ymd_and_hms(2014, 11, 28, 12, 0, 9).unwrap();
//! assert_eq!(dt.format("%Y-%m-%d %H:%M:%S").to_string(), "2014-11-28 12:00:09");
//! assert_eq!(dt.format("%a %b %e %T %Y").to_string(), "Fri Nov 28 12:00:09 2014");
//! assert_eq!(dt.format_localized("%A %e %B %Y, %T", Locale::fr_BE).to_string(), "vendredi 28 novembre 2014, 12:00:09");
//!
//! assert_eq!(dt.format("%a %b %e %T %Y").to_string(), dt.format("%c").to_string());
//! assert_eq!(dt.to_string(), "2014-11-28 12:00:09 UTC");
//! assert_eq!(dt.to_rfc2822(), "Fri, 28 Nov 2014 12:00:09 +0000");
//! assert_eq!(dt.to_rfc3339(), "2014-11-28T12:00:09+00:00");
//! assert_eq!(format!("{:?}", dt), "2014-11-28T12:00:09Z");
//!
//! // Note that milli/nanoseconds are only printed if they are non-zero
//! let dt_nano = NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_nano_opt(12, 0, 9, 1).unwrap().and_local_timezone(Utc).unwrap();
//! assert_eq!(format!("{:?}", dt_nano), "2014-11-28T12:00:09.000000001Z");
//! # }
//! # #[cfg(not(feature = "unstable-locales"))]
//! # fn test() {}
//! # if cfg!(feature = "unstable-locales") {
//! #    test();
//! # }
//! ```
//!
//! Parsing can be done with three methods:
//!
//! 1. The standard [`FromStr`](https://doc.rust-lang.org/std/str/trait.FromStr.html) trait
//!    (and [`parse`](https://doc.rust-lang.org/std/primitive.str.html#method.parse) method
//!    on a string) can be used for parsing `DateTime<FixedOffset>`, `DateTime<Utc>` and
//!    `DateTime<Local>` values. This parses what the `{:?}`
//!    ([`std::fmt::Debug`](https://doc.rust-lang.org/std/fmt/trait.Debug.html))
//!    format specifier prints, and requires the offset to be present.
//!
//! 2. [`DateTime::parse_from_str`](./struct.DateTime.html#method.parse_from_str) parses
//!    a date and time with offsets and returns `DateTime<FixedOffset>`.
//!    This should be used when the offset is a part of input and the caller cannot guess that.
//!    It *cannot* be used when the offset can be missing.
//!    [`DateTime::parse_from_rfc2822`](./struct.DateTime.html#method.parse_from_rfc2822)
//!    and
//!    [`DateTime::parse_from_rfc3339`](./struct.DateTime.html#method.parse_from_rfc3339)
//!    are similar but for well-known formats.
//!
//! 3. [`Offset::datetime_from_str`](./offset/trait.TimeZone.html#method.datetime_from_str) is
//!    similar but returns `DateTime` of given offset.
//!    When the explicit offset is missing from the input, it simply uses given offset.
//!    It issues an error when the input contains an explicit offset different
//!    from the current offset.
//!
//! More detailed control over the parsing process is available via
//! [`format`](./format/index.html) module.
//!
//! ```rust
//! use chrono::prelude::*;
//!
//! let dt = Utc.with_ymd_and_hms(2014, 11, 28, 12, 0, 9).unwrap();
//! let fixed_dt = dt.with_timezone(&FixedOffset::east_opt(9*3600).unwrap());
//!
//! // method 1
//! assert_eq!("2014-11-28T12:00:09Z".parse::<DateTime<Utc>>(), Ok(dt.clone()));
//! assert_eq!("2014-11-28T21:00:09+09:00".parse::<DateTime<Utc>>(), Ok(dt.clone()));
//! assert_eq!("2014-11-28T21:00:09+09:00".parse::<DateTime<FixedOffset>>(), Ok(fixed_dt.clone()));
//!
//! // method 2
//! assert_eq!(DateTime::parse_from_str("2014-11-28 21:00:09 +09:00", "%Y-%m-%d %H:%M:%S %z"),
//!            Ok(fixed_dt.clone()));
//! assert_eq!(DateTime::parse_from_rfc2822("Fri, 28 Nov 2014 21:00:09 +0900"),
//!            Ok(fixed_dt.clone()));
//! assert_eq!(DateTime::parse_from_rfc3339("2014-11-28T21:00:09+09:00"), Ok(fixed_dt.clone()));
//!
//! // method 3
//! assert_eq!(Utc.datetime_from_str("2014-11-28 12:00:09", "%Y-%m-%d %H:%M:%S"), Ok(dt.clone()));
//! assert_eq!(Utc.datetime_from_str("Fri Nov 28 12:00:09 2014", "%a %b %e %T %Y"), Ok(dt.clone()));
//!
//! // oops, the year is missing!
//! assert!(Utc.datetime_from_str("Fri Nov 28 12:00:09", "%a %b %e %T %Y").is_err());
//! // oops, the format string does not include the year at all!
//! assert!(Utc.datetime_from_str("Fri Nov 28 12:00:09", "%a %b %e %T").is_err());
//! // oops, the weekday is incorrect!
//! assert!(Utc.datetime_from_str("Sat Nov 28 12:00:09 2014", "%a %b %e %T %Y").is_err());
//! ```
//!
//! Again : See [`format::strftime`](./format/strftime/index.html#specifiers)
//! documentation for full syntax and list of specifiers.
//!
//! ### Conversion from and to EPOCH timestamps
//!
//! Use [`Utc.timestamp(seconds, nanoseconds)`](./offset/trait.TimeZone.html#method.timestamp)
//! to construct a [`DateTime<Utc>`](./struct.DateTime.html) from a UNIX timestamp
//! (seconds, nanoseconds that passed since January 1st 1970).
//!
//! Use [`DateTime.timestamp`](./struct.DateTime.html#method.timestamp) to get the timestamp (in seconds)
//! from a [`DateTime`](./struct.DateTime.html). Additionally, you can use
//! [`DateTime.timestamp_subsec_nanos`](./struct.DateTime.html#method.timestamp_subsec_nanos)
//! to get the number of additional number of nanoseconds.
//!
//! ```rust
//! // We need the trait in scope to use Utc::timestamp().
//! use chrono::{DateTime, TimeZone, Utc};
//!
//! // Construct a datetime from epoch:
//! let dt = Utc.timestamp(1_500_000_000, 0);
//! assert_eq!(dt.to_rfc2822(), "Fri, 14 Jul 2017 02:40:00 +0000");
//!
//! // Get epoch value from a datetime:
//! let dt = DateTime::parse_from_rfc2822("Fri, 14 Jul 2017 02:40:00 +0000").unwrap();
//! assert_eq!(dt.timestamp(), 1_500_000_000);
//! ```
//!
//! ### Individual date
//!
//! Chrono also provides an individual date type ([**`Date`**](./struct.Date.html)).
//! It also has time zones attached, and have to be constructed via time zones.
//! Most operations available to `DateTime` are also available to `Date` whenever appropriate.
//!
//! ```rust
//! use chrono::prelude::*;
//! use chrono::offset::LocalResult;
//!
//! # // these *may* fail, but only very rarely. just rerun the test if you were that unfortunate ;)
//! assert_eq!(Utc::today(), Utc::now().date());
//! assert_eq!(Local::today(), Local::now().date());
//!
//! assert_eq!(Utc.ymd_opt(2014, 11, 28).unwrap().weekday(), Weekday::Fri);
//! assert_eq!(Utc.ymd_opt(2014, 11, 31), LocalResult::None);
//! assert_eq!(NaiveDate::from_ymd_opt(2014, 11, 28).unwrap().and_hms_milli_opt(7, 8, 9, 10).unwrap().and_local_timezone(Utc).unwrap().format("%H%M%S").to_string(),
//!            "070809");
//! ```
//!
//! There is no timezone-aware `Time` due to the lack of usefulness and also the complexity.
//!
//! `DateTime` has [`date`](./struct.DateTime.html#method.date) method
//! which returns a `Date` which represents its date component.
//! There is also a [`time`](./struct.DateTime.html#method.time) method,
//! which simply returns a naive local time described below.
//!
//! ### Naive date and time
//!
//! Chrono provides naive counterparts to `Date`, (non-existent) `Time` and `DateTime`
//! as [**`NaiveDate`**](./naive/struct.NaiveDate.html),
//! [**`NaiveTime`**](./naive/struct.NaiveTime.html) and
//! [**`NaiveDateTime`**](./naive/struct.NaiveDateTime.html) respectively.
//!
//! They have almost equivalent interfaces as their timezone-aware twins,
//! but are not associated to time zones obviously and can be quite low-level.
//! They are mostly useful for building blocks for higher-level types.
//!
//! Timezone-aware `DateTime` and `Date` types have two methods returning naive versions:
//! [`naive_local`](./struct.DateTime.html#method.naive_local) returns
//! a view to the naive local time,
//! and [`naive_utc`](./struct.DateTime.html#method.naive_utc) returns
//! a view to the naive UTC time.
//!
//! ## Limitations
//!
//! Only proleptic Gregorian calendar (i.e. extended to support older dates) is supported.
//! Be very careful if you really have to deal with pre-20C dates, they can be in Julian or others.
//!
//! Date types are limited in about +/- 262,000 years from the common epoch.
//! Time types are limited in the nanosecond accuracy.
//!
//! [Leap seconds are supported in the representation but
//! Chrono doesn't try to make use of them](./naive/struct.NaiveTime.html#leap-second-handling).
//! (The main reason is that leap seconds are not really predictable.)
//! Almost *every* operation over the possible leap seconds will ignore them.
//! Consider using `NaiveDateTime` with the implicit TAI (International Atomic Time) scale
//! if you want.
//!
//! Chrono inherently does not support an inaccurate or partial date and time representation.
//! Any operation that can be ambiguous will return `None` in such cases.
//! For example, "a month later" of 2014-01-30 is not well-defined
//! and consequently `Utc.ymd_opt(2014, 1, 30).unwrap().with_month(2)` returns `None`.
//!
//! Non ISO week handling is not yet supported.
//! For now you can use the [chrono_ext](https://crates.io/crates/chrono_ext)
//! crate ([sources](https://github.com/bcourtine/chrono-ext/)).
//!
//! Advanced time zone handling is not yet supported.
//! For now you can try the [Chrono-tz](https://github.com/chronotope/chrono-tz/) crate instead.

#![doc(html_root_url = "https://docs.rs/chrono/latest/")]
#![cfg_attr(feature = "bench", feature(test))] // lib stability features as per RFC #507
#![deny(missing_docs)]
#![deny(missing_debug_implementations)]
#![warn(unreachable_pub)]
#![deny(dead_code)]
#![cfg_attr(not(any(feature = "std", test)), no_std)]
// can remove this if/when rustc-serialize support is removed
// keeps clippy happy in the meantime
#![cfg_attr(feature = "rustc-serialize", allow(deprecated))]
#![cfg_attr(docsrs, feature(doc_cfg))]

#[cfg(feature = "oldtime")]
#[cfg_attr(docsrs, doc(cfg(feature = "oldtime")))]
extern crate time as oldtime;
#[cfg(not(feature = "oldtime"))]
mod oldtime;
// this reexport is to aid the transition and should not be in the prelude!
pub use oldtime::{Duration, OutOfRangeError};

#[cfg(feature = "__doctest")]
#[cfg_attr(feature = "__doctest", cfg(doctest))]
use doc_comment::doctest;

#[cfg(feature = "__doctest")]
#[cfg_attr(feature = "__doctest", cfg(doctest))]
doctest!("../README.md");

/// A convenience module appropriate for glob imports (`use chrono::prelude::*;`).
pub mod prelude {
    #[doc(no_inline)]
    #[allow(deprecated)]
    pub use crate::Date;
    #[cfg(feature = "clock")]
    #[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
    #[doc(no_inline)]
    pub use crate::Local;
    #[cfg(feature = "unstable-locales")]
    #[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
    #[doc(no_inline)]
    pub use crate::Locale;
    #[doc(no_inline)]
    pub use crate::SubsecRound;
    #[doc(no_inline)]
    pub use crate::{DateTime, SecondsFormat};
    #[doc(no_inline)]
    pub use crate::{Datelike, Month, Timelike, Weekday};
    #[doc(no_inline)]
    pub use crate::{FixedOffset, Utc};
    #[doc(no_inline)]
    pub use crate::{NaiveDate, NaiveDateTime, NaiveTime};
    #[doc(no_inline)]
    pub use crate::{Offset, TimeZone};
}

mod date;
#[allow(deprecated)]
pub use date::{Date, MAX_DATE, MIN_DATE};

mod datetime;
#[cfg(feature = "rustc-serialize")]
#[cfg_attr(docsrs, doc(cfg(feature = "rustc-serialize")))]
pub use datetime::rustc_serialize::TsSeconds;
#[allow(deprecated)]
pub use datetime::{DateTime, SecondsFormat, MAX_DATETIME, MIN_DATETIME};

pub mod format;
/// L10n locales.
#[cfg(feature = "unstable-locales")]
#[cfg_attr(docsrs, doc(cfg(feature = "unstable-locales")))]
pub use format::Locale;
pub use format::{ParseError, ParseResult};

pub mod naive;
#[doc(no_inline)]
pub use naive::{Days, IsoWeek, NaiveDate, NaiveDateTime, NaiveTime, NaiveWeek};

pub mod offset;
#[cfg(feature = "clock")]
#[cfg_attr(docsrs, doc(cfg(feature = "clock")))]
#[doc(no_inline)]
pub use offset::Local;
#[doc(no_inline)]
pub use offset::{FixedOffset, LocalResult, Offset, TimeZone, Utc};

mod round;
pub use round::{DurationRound, RoundingError, SubsecRound};

mod weekday;
pub use weekday::{ParseWeekdayError, Weekday};

mod month;
pub use month::{Month, Months, ParseMonthError};

mod traits;
pub use traits::{Datelike, Timelike};

#[cfg(feature = "__internal_bench")]
#[doc(hidden)]
pub use naive::__BenchYearFlags;

/// Serialization/Deserialization with serde.
///
/// This module provides default implementations for `DateTime` using the [RFC 3339][1] format and various
/// alternatives for use with serde's [`with` annotation][1].
///
/// *Available on crate feature 'serde' only.*
///
/// [1]: https://tools.ietf.org/html/rfc3339
/// [2]: https://serde.rs/attributes.html#field-attributes
#[cfg(feature = "serde")]
#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
pub mod serde {
    pub use super::datetime::serde::*;
}

/// MSRV 1.42
#[cfg(test)]
#[macro_export]
macro_rules! matches {
    ($expression:expr, $(|)? $( $pattern:pat )|+ $( if $guard: expr )? $(,)?) => {
        match $expression {
            $( $pattern )|+ $( if $guard )? => true,
            _ => false
        }
    }
}