[33] 
[[OWL-Time]]
は、[[日時]]を扱う [[OWL]] の[[オントロジー]]です。
[[Semantic Web]] の世界で使われているようです(?)。

* 仕様書

[REFS[
- [7] [CITE@en[Time Ontology in OWL]]
([TIME[2017-10-16 14:39:32 +09:00]])
<https://w3c.github.io/sdw/time/>
-- [21] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#topology>
-- [22] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#time:TemporalEntity>
-- [10] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#has-beginning>
-- [18] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#has-end>
-- [19] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#has-temporal-duration>
-- [16] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#has-duration>
-- [30] [CITE@en[Time Ontology in OWL]] ([TIME[2019-06-05 22:23:30 +09:00]]) <https://w3c.github.io/sdw/time/#has-xsd-duration>
]REFS]

* データモデル

[FIG(short list)[ [31] [[OWL-Time]] の[[クラス]]
- [CODE[:TemporalPosition]]
- [CODE[:TemporalEntity]]
-- [CODE[:Instant]]
-- [CODE[:Interval]]
- [CODE[:TemporalDuration]]
-- [CODE[:TemporalUnit]]
]FIG]

[9] [[グレゴリオ暦]]以外の[[暦法]]も扱えることになっており、
任意の[[時間帯]]も扱えるという立て付けにはなってはいますが、
大変怪しいものです。詳しくは各項。

[FIG(short list)[ [32] [[OWL-Time]] の[[日時システム]]
- [CODE[:TRS]]
- [CODE[:TimeZone]]
- [CODE[:MonthOfYear]]
- [CODE[:DayOfWeek]]
- [CODE[:genericYear]]
- [CODE[:genericMonth]]
- [CODE[:genericDay]]
]FIG]

* [CODE[:TemporalEntity]]

[23] [[OWL-Time]] は[[時間軸]]上の位置として [CODE[:Instant]] と [CODE[:Interval]] 
を持っており、
その共通の[[親クラス]]を
[DFN[[CODE[:TemporalEntity]]]] [SRC[>>22]] としています。

[24] [CODE[:Interval]] と [CODE[:Instant]] は別物とされていますが、
共に [CODE[:before][time:before]] と [CODE[:after][time:after]]
を持ち、 [CODE[:Instant]] は長さ0の interval とみなせる
(instant は interval の特殊形である) [SRC[>>21]]
とされています。

;; [25] それを徹底して [CODE[:Interval]] を [CODE[:Instant]] の[[親クラス]]にせず共通の[[親クラス]]
[CODE[:TemporalEntity]] を設けたのは、さすがに実用上不便だからでしょうか。

[28] [CODE[:Interval]] と [CODE[:Instant]] は排他的とはされておらず、
どちらでもあるとすることは可能です。 ([CODE[:Interval]] に[[子クラス]]
[CODE[:ProperInterval]] があり、 [CODE[:ProperInterval]] と
[CODE[:Instant]] は排他的とされています。)

[26] [CODE[:TemporalEntity]] は [CODE[owl:Class]] です。 [SRC[>>22]]

[FIG(short list)[ [27] [[特性]]
- [CODE[:before][time:before]]
- [CODE[:after][time:after]]
- [CODE[:hasBeginning]]
- [CODE[:hasEnd]]
- [CODE[:hasTemporalDuration]]
- [CODE[:hasDuration]]
- [CODE[:hasDurationDescription]]
- [CODE[:hasXSDDuration]]
]FIG]

[11] 
[DFN[[CODE[:hasBeginning]]]],
[DFN[[CODE[:hasEnd]]]]
はそれぞれ始まりと終わりの
[CODE[time:Instant]]
を指定するものです。 [SRC[>>10, >>18]]

[17] 
[DFN[[CODE[:hasTemporalDuration]]]]
とその[[部分特性]]の
[DFN[[CODE[:hasDuration]]]],
[DFN[[CODE[:hasDurationDescription]]]]
は
[CODE[:TemporalDuration]],
[CODE[:Duration]],
[CODE[:DurationDescription]]
を指定するものです。 [SRC[>>16, >>19]]

[29] 
[DFN[[CODE[:hasXSDDuration]]]]
は
[CODE[xsd:duration]]
の値を指定するものです。
[SRC[>>30]]


-*-*-

[20] 
[DFN[[CODE[:hasTime]]]]
は、
[CODE[:TemporalEntity]]
を指定する[[特性]]です。 [SRC[>>19]]

* 応用

[35] [CITE@en[Data Catalog Vocabulary (DCAT) - Version 2]], [TIME[2020-02-04 05:17:18 +09:00]] <https://w3c.github.io/dxwg/dcat/#Property:period_has_beginning>

* 歴史

[15] [CITE[DAML-Time Homepage]] ([TIME[2019-06-10 18:22:38 +09:00]]) <https://web.archive.org/web/20070501025728/http://www.cs.rochester.edu/~ferguson/daml/>

[13] [CITE[OWL-Time Homepage]] ([TIME[2019-06-10 18:20:07 +09:00]]) <https://web.archive.org/web/20070503211843/http://www.isi.edu/%7Epan/OWL-Time.html>

[14] [CITE[Time Ontology in OWL]] ([TIME[2017-10-02 20:00:49 +09:00]]) <https://www.w3.org/TR/2006/WD-owl-time-20060927/>


[1] [CITE@en[Time Ontology in OWL]]
([TIME[2016-07-12 18:38:43 +09:00]])
<https://www.w3.org/TR/owl-time/>


[2] [CITE@en[Time Ontology in OWL]]
([TIME[2016-07-12 18:38:43 +09:00]])
<https://www.w3.org/TR/2016/WD-owl-time-20160712/>

[FIG(quote)[
[FIGCAPTION[
[3] [CITE@en[QB4ST: RDF Data Cube extensions for spatio-temporal components]]
([TIME[2017-04-13 23:56:44 +09:00]])
<https://www.w3.org/TR/2017/NOTE-qb4st-20170418/#h-owl-time>
]FIGCAPTION]

> QB4ST extends RDF Data Cube by specifying use of OWL-Time as the appropriate ontology for temporal reference systems.

]FIG]


[4] [CITE@en[Time Ontology in OWL]]
([TIME[2017-06-06 17:27:51 +09:00]])
<https://www.w3.org/TR/2017/CR-owl-time-20170606/>

[5] [CITE@en[Time Ontology in OWL]]
([TIME[2017-09-04 23:28:54 +09:00]])
<https://www.w3.org/TR/2017/PR-owl-time-20170907/>

[6] [CITE@en[Time Ontology in OWL]]
([TIME[2017-10-16 22:02:17 +09:00]])
<https://www.w3.org/TR/2017/REC-owl-time-20171019/>


[8] [CITE@en[OWL Time Ontology adoption - Spatial Data on the Web Working Group]]
([TIME[2017-10-27 12:02:17 +09:00]])
<https://www.w3.org/2015/spatial/wiki/OWL_Time_Ontology_adoption>


[12] [CITE@en[sdw/time at gh-pages · w3c/sdw]]
([TIME[2019-06-09 15:52:37 +09:00]])
<https://github.com/w3c/sdw/tree/gh-pages/time>

[34] [CITE@en[History for time - w3c/sdw]]
([TIME[2019-12-13 15:34:13 +09:00]])
<https://github.com/w3c/sdw/commits/gh-pages/time>

[36] [CITE@en[Time Ontology in OWL]], [TIME[2020-03-26T05:17:25.000Z]], [TIME[2021-01-13T08:45:53.375Z]] <https://www.w3.org/TR/2020/CR-owl-time-20200326/>