* 仕様書

[1] [CITE@en-us[UTS #35: Unicode LDML: Dates]]
([TIME[2015-09-17 07:19:07 +09:00]] 版)
<http://www.unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table>


[3] [CITE@en-us[UTS #35: Unicode LDML: Dates]]
([TIME[2015-09-17 07:19:07 +09:00]] 版)
<http://www.unicode.org/reports/tr35/tr35-dates.html#Date_Format_Patterns>

[4] [CITE[Date/Time Patterns - CLDR - Unicode Common Locale Data Repository]] ([TIME[2016-06-24 13:52:06 +09:00]]) <http://cldr.unicode.org/translation/date-time-patterns>

* 拡張

[9] [[7date]]

* 応用


[5] 
[[ICU]] が実装しています。
[SRC[>>391]]

[8] 実質的に[[参照実装]]でしょう。

-
[391] 
[CITE@en-US[Formatting Dates and Times - [[ICU]] Documentation]], [TIME[2022-07-01T16:00:39.000Z]], [TIME[2022-07-10T11:58:14.302Z]] <https://unicode-org.github.io/icu/userguide/format_parse/datetime/#dateformat>



[7] 
[[Apple]] の [[Cocoa]] 
[WEAK[([[Mac OS X]] や [[iOS]] で使われている)]]
で実装され、
[[Objective-C]]
や
[[Swift]] のような[[プログラミング言語]]で使われています。
[SRC[>>6]]

[FIG(quote)[
[FIGCAPTION[
[6] 
[CITE@en[Date Formatters]], [TIME[2021-10-29T17:46:37.000Z]], [TIME[2022-06-21T09:14:07.042Z]] <https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html#%2F%2Fapple_ref%2Fdoc%2Fuid%2FTP40002369-SW13>
]FIGCAPTION]

>To specify a custom fixed format for a date formatter, you use setDateFormat:. The format string uses the format patterns from the Unicode Technical Standard #35. 
]FIG]


[FIG(quote)[
[FIGCAPTION[
[2] [CITE@en[Model for Tabular Data and Metadata on the Web]]
([TIME[2015-12-03 19:28:42 +09:00]] 版)
<http://www.w3.org/TR/2015/REC-tabular-data-model-20151217/#h-formats-for-dates-and-times>
]FIGCAPTION]

> The supported date and time format patterns listed here are expressed in terms of the date field symbols defined in '''['''UAX35''']'''. These formats must be recognised by implementations and must be interpreted as defined in that specification. Implementations may additionally recognise other date format patterns. Implementations must issue a warning if the date format pattern is invalid or not recognised and proceed as if no date format pattern had been provided.

]FIG]



* 関連

[SEE[ [[暦年週年バグ]] ]]

[SEE[ [[時間帯パターン]] ]]

* メモ