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
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
// This is a part of Chrono.
// See README.md and LICENSE.txt for details.

//! # 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)
//!
//! Any significant changes to Chrono are documented in
//! the [`CHANGELOG.md`](https://github.com/chronotope/chrono/blob/master/CHANGELOG.md) file.
//!
//! ## Usage
//!
//! Put this in your `Cargo.toml`:
//!
//! ```toml
//! [dependencies]
//! chrono = "0.4"
//! ```
//!
//! Or, if you want [Serde](https://github.com/serde-rs/serde) include the
//! feature like this:
//!
//! ```toml
//! [dependencies]
//! chrono = { version = "0.4", features = ["serde"] }
//! ```
//!
//! Then put this in your crate root:
//!
//! ```rust
//! extern crate chrono;
//! ```
//!
//! Avoid using `use chrono::*;` as Chrono exports several modules other than types.
//! If you prefer the glob imports, use the following instead:
//!
//! ```rust
//! use chrono::prelude::*;
//! ```
//!
//! ## Overview
//!
//! ### Duration
//!
//! Chrono currently uses
//! the [`time::Duration`](https://docs.rs/time/0.1.40/time/struct.Duration.html) type
//! from the `time` crate to represent the magnitude of a time span.
//! Since this has the same name to 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.
//!
//! Chrono does not yet natively support
//! the standard [`Duration`](https://docs.rs/time/0.1.40/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.ymd(2014, 7, 8).and_hms(9, 10, 11); // `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(9, 10, 11));
//! // July 8 is Tuesday in ISO week 28 of the year 2014.
//! assert_eq!(dt, Utc.isoywd(2014, 28, Weekday::Tue).and_hms(9, 10, 11));
//!
//! let dt = Utc.ymd(2014, 7, 8).and_hms_milli(9, 10, 11, 12); // `2014-07-08T09:10:11.012Z`
//! assert_eq!(dt, Utc.ymd(2014, 7, 8).and_hms_micro(9, 10, 11, 12_000));
//! assert_eq!(dt, Utc.ymd(2014, 7, 8).and_hms_nano(9, 10, 11, 12_000_000));
//!
//! // dynamic verification
//! assert_eq!(Utc.ymd_opt(2014, 7, 8).and_hms_opt(21, 15, 33),
//!            LocalResult::Single(Utc.ymd(2014, 7, 8).and_hms(21, 15, 33)));
//! 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.ymd(2014, 7, 8).and_hms_milli(9, 10, 11, 12);
//! let fixed_dt = FixedOffset::east(9 * 3600).ymd(2014, 7, 8).and_hms_milli(18, 10, 11, 12);
//! 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
//! # extern crate chrono; extern crate time; fn main() {
//! use chrono::prelude::*;
//! use time::Duration;
//!
//! # /* we intentionally fake the datetime...
//! // assume this returned `2014-11-28T21:45:59.324310806+09:00`:
//! let dt = Local::now();
//! # */ // up to here. we now define a fixed datetime for the illustrative purpose.
//! # let dt = FixedOffset::east(9*3600).ymd(2014, 11, 28).and_hms_nano(21, 45, 59, 324310806);
//!
//! // 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, ..., Sat=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(9 * 3600));
//! assert_eq!(dt.with_timezone(&Utc), Utc.ymd(2014, 11, 28).and_hms_nano(12, 45, 59, 324310806));
//!
//! // 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.ymd(2014, 11, 14).and_hms(8, 9, 10);
//! let dt2 = Utc.ymd(2014, 11, 14).and_hms(10, 9, 8);
//! 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.ymd(1970, 1, 1).and_hms(0, 0, 0) + Duration::seconds(1_000_000_000),
//!            Utc.ymd(2001, 9, 9).and_hms(1, 46, 40));
//! assert_eq!(Utc.ymd(1970, 1, 1).and_hms(0, 0, 0) - Duration::seconds(1_000_000_000),
//!            Utc.ymd(1938, 4, 24).and_hms(22, 13, 20));
//! # }
//! ```
//!
//! ### 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.
//!
//! ```rust
//! use chrono::prelude::*;
//!
//! let dt = Utc.ymd(2014, 11, 28).and_hms(12, 0, 9);
//! 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("%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 = Utc.ymd(2014, 11, 28).and_hms_nano(12, 0, 9, 1);
//! assert_eq!(format!("{:?}", dt_nano), "2014-11-28T12:00:09.000000001Z");
//! ```
//!
//! 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.ymd(2014, 11, 28).and_hms(12, 0, 9);
//! let fixed_dt = dt.with_timezone(&FixedOffset::east(9*3600));
//!
//! // 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
//! # use chrono::DateTime;
//! # use chrono::Utc;
//! // We need the trait in scope to use Utc::timestamp().
//! use chrono::TimeZone;
//!
//! // 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(2014, 11, 28).weekday(), Weekday::Fri);
//! assert_eq!(Utc.ymd_opt(2014, 11, 31), LocalResult::None);
//! assert_eq!(Utc.ymd(2014, 11, 28).and_hms_milli(7, 8, 9, 10).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(2014, 1, 30).with_month(2)` returns `None`.
//!
//! 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(bench, feature(test))] // lib stability features as per RFC #507
#![deny(missing_docs)]
#![deny(missing_debug_implementations)]

// The explicit 'static lifetimes are still needed for rustc 1.13-16
// backward compatibility, and this appeases clippy. If minimum rustc
// becomes 1.17, should be able to remove this, those 'static lifetimes,
// and use `static` in a lot of places `const` is used now.
//
// Similarly, redundant_field_names lints on not using the
// field-init-shorthand, which was stabilized in rust 1.17.
//
// Changing trivially_copy_pass_by_ref would require an incompatible version
// bump.
#![cfg_attr(feature = "cargo-clippy", allow(
    const_static_lifetime,
    redundant_field_names,
    trivially_copy_pass_by_ref,
))]

#[cfg(feature="clock")]
extern crate time as oldtime;
extern crate num_integer;
extern crate num_traits;
#[cfg(feature = "rustc-serialize")]
extern crate rustc_serialize;
#[cfg(feature = "serde")]
extern crate serde as serdelib;

// this reexport is to aid the transition and should not be in the prelude!
pub use oldtime::Duration;

#[cfg(feature="clock")]
#[doc(no_inline)] pub use offset::Local;
#[doc(no_inline)] pub use offset::{TimeZone, Offset, LocalResult, Utc, FixedOffset};
#[doc(no_inline)] pub use naive::{NaiveDate, IsoWeek, NaiveTime, NaiveDateTime};
pub use date::{Date, MIN_DATE, MAX_DATE};
pub use datetime::{DateTime, SecondsFormat};
#[cfg(feature = "rustc-serialize")]
pub use datetime::rustc_serialize::TsSeconds;
pub use format::{ParseError, ParseResult};
pub use round::SubsecRound;

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

// useful throughout the codebase
macro_rules! try_opt {
    ($e:expr) => (match $e { Some(v) => v, None => return None })
}

mod div;
#[cfg(not(feature="clock"))]
mod oldtime;
pub mod offset;
pub mod naive {
    //! Date and time types which do not concern about the timezones.
    //!
    //! They are primarily building blocks for other types
    //! (e.g. [`TimeZone`](../offset/trait.TimeZone.html)),
    //! but can be also used for the simpler date and time handling.

    mod internals;
    mod date;
    mod isoweek;
    mod time;
    mod datetime;

    pub use self::date::{NaiveDate, MIN_DATE, MAX_DATE};
    pub use self::isoweek::IsoWeek;
    pub use self::time::NaiveTime;
    pub use self::datetime::NaiveDateTime;
    #[cfg(feature = "rustc-serialize")]
    #[allow(deprecated)]
    pub use self::datetime::rustc_serialize::TsSeconds;


    /// Serialization/Deserialization of naive types in alternate formats
    ///
    /// The various modules in here are intended to be used with serde's [`with`
    /// annotation][1] to serialize as something other than the default [RFC
    /// 3339][2] format.
    ///
    /// [1]: https://serde.rs/attributes.html#field-attributes
    /// [2]: https://tools.ietf.org/html/rfc3339
    #[cfg(feature = "serde")]
    pub mod serde {
        pub use super::datetime::serde::*;
    }
}
mod date;
mod datetime;
pub mod format;
mod round;

/// Serialization/Deserialization in alternate formats
///
/// The various modules in here are intended to be used with serde's [`with`
/// annotation][1] to serialize as something other than the default [RFC
/// 3339][2] format.
///
/// [1]: https://serde.rs/attributes.html#field-attributes
/// [2]: https://tools.ietf.org/html/rfc3339
#[cfg(feature = "serde")]
pub mod serde {
    pub use super::datetime::serde::*;
}

/// The day of week.
///
/// The order of the days of week depends on the context.
/// (This is why this type does *not* implement `PartialOrd` or `Ord` traits.)
/// One should prefer `*_from_monday` or `*_from_sunday` methods to get the correct result.
#[derive(PartialEq, Eq, Copy, Clone, Debug, Hash)]
#[cfg_attr(feature = "rustc-serialize", derive(RustcEncodable, RustcDecodable))]
pub enum Weekday {
    /// Monday.
    Mon = 0,
    /// Tuesday.
    Tue = 1,
    /// Wednesday.
    Wed = 2,
    /// Thursday.
    Thu = 3,
    /// Friday.
    Fri = 4,
    /// Saturday.
    Sat = 5,
    /// Sunday.
    Sun = 6,
}

impl Weekday {
    /// The next day in the week.
    ///
    /// `w`:        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
    /// ----------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
    /// `w.succ()`: | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun` | `Mon`
    #[inline]
    pub fn succ(&self) -> Weekday {
        match *self {
            Weekday::Mon => Weekday::Tue,
            Weekday::Tue => Weekday::Wed,
            Weekday::Wed => Weekday::Thu,
            Weekday::Thu => Weekday::Fri,
            Weekday::Fri => Weekday::Sat,
            Weekday::Sat => Weekday::Sun,
            Weekday::Sun => Weekday::Mon,
        }
    }

    /// The previous day in the week.
    ///
    /// `w`:        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
    /// ----------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
    /// `w.pred()`: | `Sun` | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat`
    #[inline]
    pub fn pred(&self) -> Weekday {
        match *self {
            Weekday::Mon => Weekday::Sun,
            Weekday::Tue => Weekday::Mon,
            Weekday::Wed => Weekday::Tue,
            Weekday::Thu => Weekday::Wed,
            Weekday::Fri => Weekday::Thu,
            Weekday::Sat => Weekday::Fri,
            Weekday::Sun => Weekday::Sat,
        }
    }

    /// Returns a day-of-week number starting from Monday = 1. (ISO 8601 weekday number)
    ///
    /// `w`:                      | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
    /// ------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
    /// `w.number_from_monday()`: | 1     | 2     | 3     | 4     | 5     | 6     | 7
    #[inline]
    pub fn number_from_monday(&self) -> u32 {
        match *self {
            Weekday::Mon => 1,
            Weekday::Tue => 2,
            Weekday::Wed => 3,
            Weekday::Thu => 4,
            Weekday::Fri => 5,
            Weekday::Sat => 6,
            Weekday::Sun => 7,
        }
    }

    /// Returns a day-of-week number starting from Sunday = 1.
    ///
    /// `w`:                      | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
    /// ------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
    /// `w.number_from_sunday()`: | 2     | 3     | 4     | 5     | 6     | 7     | 1
    #[inline]
    pub fn number_from_sunday(&self) -> u32 {
        match *self {
            Weekday::Mon => 2,
            Weekday::Tue => 3,
            Weekday::Wed => 4,
            Weekday::Thu => 5,
            Weekday::Fri => 6,
            Weekday::Sat => 7,
            Weekday::Sun => 1,
        }
    }

    /// Returns a day-of-week number starting from Monday = 0.
    ///
    /// `w`:                        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
    /// --------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
    /// `w.num_days_from_monday()`: | 0     | 1     | 2     | 3     | 4     | 5     | 6
    #[inline]
    pub fn num_days_from_monday(&self) -> u32 {
        match *self {
            Weekday::Mon => 0,
            Weekday::Tue => 1,
            Weekday::Wed => 2,
            Weekday::Thu => 3,
            Weekday::Fri => 4,
            Weekday::Sat => 5,
            Weekday::Sun => 6,
        }
    }

    /// Returns a day-of-week number starting from Sunday = 0.
    ///
    /// `w`:                        | `Mon` | `Tue` | `Wed` | `Thu` | `Fri` | `Sat` | `Sun`
    /// --------------------------- | ----- | ----- | ----- | ----- | ----- | ----- | -----
    /// `w.num_days_from_sunday()`: | 1     | 2     | 3     | 4     | 5     | 6     | 0
    #[inline]
    pub fn num_days_from_sunday(&self) -> u32 {
        match *self {
            Weekday::Mon => 1,
            Weekday::Tue => 2,
            Weekday::Wed => 3,
            Weekday::Thu => 4,
            Weekday::Fri => 5,
            Weekday::Sat => 6,
            Weekday::Sun => 0,
        }
    }
}

/// Any weekday can be represented as an integer from 0 to 6, which equals to
/// [`Weekday::num_days_from_monday`](#method.num_days_from_monday) in this implementation.
/// Do not heavily depend on this though; use explicit methods whenever possible.
impl num_traits::FromPrimitive for Weekday {
    #[inline]
    fn from_i64(n: i64) -> Option<Weekday> {
        match n {
            0 => Some(Weekday::Mon),
            1 => Some(Weekday::Tue),
            2 => Some(Weekday::Wed),
            3 => Some(Weekday::Thu),
            4 => Some(Weekday::Fri),
            5 => Some(Weekday::Sat),
            6 => Some(Weekday::Sun),
            _ => None,
        }
    }

    #[inline]
    fn from_u64(n: u64) -> Option<Weekday> {
        match n {
            0 => Some(Weekday::Mon),
            1 => Some(Weekday::Tue),
            2 => Some(Weekday::Wed),
            3 => Some(Weekday::Thu),
            4 => Some(Weekday::Fri),
            5 => Some(Weekday::Sat),
            6 => Some(Weekday::Sun),
            _ => None,
        }
    }
}

use std::fmt;

/// An error resulting from reading `Weekday` value with `FromStr`.
#[derive(Clone, PartialEq)]
pub struct ParseWeekdayError {
    _dummy: (),
}

impl fmt::Debug for ParseWeekdayError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "ParseWeekdayError {{ .. }}")
    }
}

// the actual `FromStr` implementation is in the `format` module to leverage the existing code

#[cfg(feature = "serde")]
mod weekday_serde {
    use super::Weekday;
    use std::fmt;
    use serdelib::{ser, de};

    impl ser::Serialize for Weekday {
        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
            where S: ser::Serializer
        {
            serializer.serialize_str(&format!("{:?}", self))
        }
    }

    struct WeekdayVisitor;

    impl<'de> de::Visitor<'de> for WeekdayVisitor {
        type Value = Weekday;

        fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
            write!(f, "Weekday")
        }

        fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
            where E: de::Error
        {
            value.parse().map_err(|_| E::custom("short or long weekday names expected"))
        }
    }

    impl<'de> de::Deserialize<'de> for Weekday {
        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
            where D: de::Deserializer<'de>
        {
            deserializer.deserialize_str(WeekdayVisitor)
        }
    }

    #[cfg(test)]
    extern crate serde_json;

    #[test]
    fn test_serde_serialize() {
        use self::serde_json::to_string;
        use Weekday::*;

        let cases: Vec<(Weekday, &str)> = vec![
            (Mon, "\"Mon\""),
            (Tue, "\"Tue\""),
            (Wed, "\"Wed\""),
            (Thu, "\"Thu\""),
            (Fri, "\"Fri\""),
            (Sat, "\"Sat\""),
            (Sun, "\"Sun\""),
        ];

        for (weekday, expected_str) in cases {
            let string = to_string(&weekday).unwrap();
            assert_eq!(string, expected_str);
        }
    }

    #[test]
    fn test_serde_deserialize() {
        use self::serde_json::from_str;
        use Weekday::*;

        let cases: Vec<(&str, Weekday)> = vec![
            ("\"mon\"", Mon),
            ("\"MONDAY\"", Mon),
            ("\"MonDay\"", Mon),
            ("\"mOn\"", Mon),
            ("\"tue\"", Tue),
            ("\"tuesday\"", Tue),
            ("\"wed\"", Wed),
            ("\"wednesday\"", Wed),
            ("\"thu\"", Thu),
            ("\"thursday\"", Thu),
            ("\"fri\"", Fri),
            ("\"friday\"", Fri),
            ("\"sat\"", Sat),
            ("\"saturday\"", Sat),
            ("\"sun\"", Sun),
            ("\"sunday\"", Sun),
        ];

        for (str, expected_weekday) in cases {
            let weekday = from_str::<Weekday>(str).unwrap();
            assert_eq!(weekday, expected_weekday);
        }

        let errors: Vec<&str> = vec![
            "\"not a weekday\"",
            "\"monDAYs\"",
            "\"mond\"",
            "mon",
            "\"thur\"",
            "\"thurs\"",
        ];

        for str in errors {
            from_str::<Weekday>(str).unwrap_err();
        }
    }
}

/// The common set of methods for date component.
pub trait Datelike: Sized {
    /// Returns the year number in the [calendar date](./naive/struct.NaiveDate.html#calendar-date).
    fn year(&self) -> i32;

    /// Returns the absolute year number starting from 1 with a boolean flag,
    /// which is false when the year predates the epoch (BCE/BC) and true otherwise (CE/AD).
    #[inline]
    fn year_ce(&self) -> (bool, u32) {
        let year = self.year();
        if year < 1 {
            (false, (1 - year) as u32)
        } else {
            (true, year as u32)
        }
    }

    /// Returns the month number starting from 1.
    ///
    /// The return value ranges from 1 to 12.
    fn month(&self) -> u32;

    /// Returns the month number starting from 0.
    ///
    /// The return value ranges from 0 to 11.
    fn month0(&self) -> u32;

    /// Returns the day of month starting from 1.
    ///
    /// The return value ranges from 1 to 31. (The last day of month differs by months.)
    fn day(&self) -> u32;

    /// Returns the day of month starting from 0.
    ///
    /// The return value ranges from 0 to 30. (The last day of month differs by months.)
    fn day0(&self) -> u32;

    /// Returns the day of year starting from 1.
    ///
    /// The return value ranges from 1 to 366. (The last day of year differs by years.)
    fn ordinal(&self) -> u32;

    /// Returns the day of year starting from 0.
    ///
    /// The return value ranges from 0 to 365. (The last day of year differs by years.)
    fn ordinal0(&self) -> u32;

    /// Returns the day of week.
    fn weekday(&self) -> Weekday;

    /// Returns the ISO week.
    fn iso_week(&self) -> IsoWeek;

    /// Makes a new value with the year number changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_year(&self, year: i32) -> Option<Self>;

    /// Makes a new value with the month number (starting from 1) changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_month(&self, month: u32) -> Option<Self>;

    /// Makes a new value with the month number (starting from 0) changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_month0(&self, month0: u32) -> Option<Self>;

    /// Makes a new value with the day of month (starting from 1) changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_day(&self, day: u32) -> Option<Self>;

    /// Makes a new value with the day of month (starting from 0) changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_day0(&self, day0: u32) -> Option<Self>;

    /// Makes a new value with the day of year (starting from 1) changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_ordinal(&self, ordinal: u32) -> Option<Self>;

    /// Makes a new value with the day of year (starting from 0) changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_ordinal0(&self, ordinal0: u32) -> Option<Self>;

    /// Returns the number of days since January 1, Year 1 (aka Day 1) in the
    /// proleptic Gregorian calendar.
    ///
    /// # Example:
    ///
    /// ~~~
    /// use chrono::{NaiveDate, Datelike};
    /// assert_eq!(NaiveDate::from_ymd(1970, 1, 1).num_days_from_ce(), 719163);
    /// assert_eq!(NaiveDate::from_ymd(0, 1, 1).num_days_from_ce(), -365);
    /// ~~~
    fn num_days_from_ce(&self) -> i32 {
        // we know this wouldn't overflow since year is limited to 1/2^13 of i32's full range.
        let mut year = self.year() - 1;
        let mut ndays = 0;
        if year < 0 {
            let excess = 1 + (-year) / 400;
            year += excess * 400;
            ndays -= excess * 146_097;
        }
        let div_100 = year / 100;
        ndays += ((year * 1461) >> 2) - div_100 + (div_100 >> 2);
        ndays + self.ordinal() as i32
    }
}

/// The common set of methods for time component.
pub trait Timelike: Sized {
    /// Returns the hour number from 0 to 23.
    fn hour(&self) -> u32;

    /// Returns the hour number from 1 to 12 with a boolean flag,
    /// which is false for AM and true for PM.
    #[inline]
    fn hour12(&self) -> (bool, u32) {
        let hour = self.hour();
        let mut hour12 = hour % 12;
        if hour12 == 0 {
            hour12 = 12;
        }
        (hour >= 12, hour12)
    }

    /// Returns the minute number from 0 to 59.
    fn minute(&self) -> u32;

    /// Returns the second number from 0 to 59.
    fn second(&self) -> u32;

    /// Returns the number of nanoseconds since the whole non-leap second.
    /// The range from 1,000,000,000 to 1,999,999,999 represents
    /// the [leap second](./naive/struct.NaiveTime.html#leap-second-handling).
    fn nanosecond(&self) -> u32;

    /// Makes a new value with the hour number changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_hour(&self, hour: u32) -> Option<Self>;

    /// Makes a new value with the minute number changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    fn with_minute(&self, min: u32) -> Option<Self>;

    /// Makes a new value with the second number changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    /// As with the [`second`](#tymethod.second) method,
    /// the input range is restricted to 0 through 59.
    fn with_second(&self, sec: u32) -> Option<Self>;

    /// Makes a new value with nanoseconds since the whole non-leap second changed.
    ///
    /// Returns `None` when the resulting value would be invalid.
    /// As with the [`nanosecond`](#tymethod.nanosecond) method,
    /// the input range can exceed 1,000,000,000 for leap seconds.
    fn with_nanosecond(&self, nano: u32) -> Option<Self>;

    /// Returns the number of non-leap seconds past the last midnight.
    #[inline]
    fn num_seconds_from_midnight(&self) -> u32 {
        self.hour() * 3600 + self.minute() * 60 + self.second()
    }
}

#[cfg(test)] extern crate num_iter;

#[test]
fn test_readme_doomsday() {
    use num_iter::range_inclusive;

    for y in range_inclusive(naive::MIN_DATE.year(), naive::MAX_DATE.year()) {
        // even months
        let d4 = NaiveDate::from_ymd(y, 4, 4);
        let d6 = NaiveDate::from_ymd(y, 6, 6);
        let d8 = NaiveDate::from_ymd(y, 8, 8);
        let d10 = NaiveDate::from_ymd(y, 10, 10);
        let d12 = NaiveDate::from_ymd(y, 12, 12);

        // nine to five, seven-eleven
        let d59 = NaiveDate::from_ymd(y, 5, 9);
        let d95 = NaiveDate::from_ymd(y, 9, 5);
        let d711 = NaiveDate::from_ymd(y, 7, 11);
        let d117 = NaiveDate::from_ymd(y, 11, 7);

        // "March 0"
        let d30 = NaiveDate::from_ymd(y, 3, 1).pred();

        let weekday = d30.weekday();
        let other_dates = [d4, d6, d8, d10, d12, d59, d95, d711, d117];
        assert!(other_dates.iter().all(|d| d.weekday() == weekday));
    }
}