ISO 8601

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=ISO 8601=
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<entry-title>ISO 8601</entry-title>
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The '''International Standards Organisation''' standard, number ''8601''' is an international standard for date and time representations.
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The '''International Standards Organisation''''s standard, number '''8601''' is an international standard for date and time representations. It is used for all date-time representations in microformats, as well as a number of other formats ([[HTML5]] <code>&lt;time&gt;</code> element &amp; <code>datetime</code> attribute, XML Schema Datatypes, RDF, Atom).
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<div style="float: right">https://sslimgs.xkcd.com/comics/iso_8601.png
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<small style="float: right">Image: [https://xkcd.com/1179/ XKCD]</small>
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</div>
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In addition, ISO 8601 dates in particular are the most globally unambiguously human readable/writeable date format and thus should always be used on the (world wide) web.
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==Overview==
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The following are good prose overviews of ISO 8601:
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* [http://www.cl.cam.ac.uk/~mgk25/iso-time.html ISO 8601 summary by Markus Kuhn]
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* [http://en.wikipedia.org/wiki/ISO_8601 ISO 8601 on Wikipedia]
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==Microformats==
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microformats in general use a subset of ISO8601 - preferring uses which are more human readable (requiring hyphens in dates, and colons in times).
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All date-time properties in microformats use ISO8601 values. E.g.
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* all <code>dt-*</code> properties in [[microformats2]]
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* all classic microformats's date-time properties, including:
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**[[hAtom]] - <code>published</code>, <code>updated</code>
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**[[hCalendar]] - <code>dtstart</code>, <code>dtend</code>
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**[[hCard]] - <code>bday</code>
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**[[hReview]] - <code>dtreviewed</code>
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__TOC__
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== HTML5 ==
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[[HTML5]] uses both a subset of ISO 8601 for dates, times, durations for the <code>&lt;time&gt;</code> element, as well as an extended (and more human friendly) duration format.
==<nowiki>RFC 3339</nowiki>==
==<nowiki>RFC 3339</nowiki>==
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RFC 3339 defines a profile of ISO 8601 for the use in Internet protocols and standards. It explicitly excludes durations and dates before the [http://en.wikipedia.org/wiki/Common_era common era]. The more complex formats like week numbers and ordinal day are not permitted (see <nowiki>RFC 3339</nowiki>, section 5.6).
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RFC 3339 defines a profile of ISO 8601 for the use in Internet protocols and standards.
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*It explicitly excludes durations and dates before the [http://en.wikipedia.org/wiki/Common_era common era].
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*The more complex formats like week numbers and ordinal day are not permitted (see <nowiki>RFC 3339</nowiki>, section 5.6).  
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==ISO 8601 implementations in programming libraries==
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* JodaTime - the Java date-time library - [http://joda-time.sourceforge.net/cal_iso.html ISO8601 Java calendar system]
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* Perl: DateTime::Format::ISO8601
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* Ruby 1.9 implements an iso8601 method in the Date STDLIB but it does not handle ordinal dates.
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* Glenn Jones' [https://github.com/glennjones/microformat-node microformat-node] parser includes isodate.js, a Node.js implementation of (some of) ISO 8601.
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* Python: [https://pypi.python.org/pypi/iso8601 iso8601]
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{{ToDo}} document more implementations.
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== FAQ ==
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=== Why hyphens in dates ===
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Q: Must I use the hyphens?[https://twitter.com/edburns/status/368063860835897344]
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A: You <em>should</em> always use hyphens in ISO 8601 dates because that makes them more readable, and thus more human friendly.
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Also, using hyphens helps clearly distinguish different uses for different granularities of dates, e.g.:
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* 2013-08-19 - just the day
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* 2013-08 - the whole month
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* 2013 - the entire year
==Issues==
==Issues==
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* Should we restrict microformats' use of ISO 8601 to <nowiki>RFC 3339</nowiki> values? [[User:AndyMabbett|Andy Mabbett]]
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None currently.
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* How should dates before the common era be marked up? [[User:AndyMabbett|Andy Mabbett]]
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Resolved issues: [[iso-8601-issues-resolved]].
==See also==
==See also==
*[http://en.wikipedia.org/wiki/ISO_8601 ISO 8601 on Wikipedia]
*[http://en.wikipedia.org/wiki/ISO_8601 ISO 8601 on Wikipedia]
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** [http://en.wikipedia.org/wiki/ISO_8601_usage ISO 8601 usage on Wikipedia]
* [http://isotc.iso.org/livelink/livelink/4021199/ISO_8601_2004_E.zip?func=doc.Fetch&nodeid=4021199 ISO 8601:2004(E) from ISO] (zip-pdf, 228KB)
* [http://isotc.iso.org/livelink/livelink/4021199/ISO_8601_2004_E.zip?func=doc.Fetch&nodeid=4021199 ISO 8601:2004(E) from ISO] (zip-pdf, 228KB)
* [http://www.iso.org/iso/en/prods-services/popstds/datesandtime.html Summary of 8601 by ISO]
* [http://www.iso.org/iso/en/prods-services/popstds/datesandtime.html Summary of 8601 by ISO]
* [http://isotc.iso.org/livelink/livelink/fetch/2000/2122/138351/138352/customview.html?func=ll&objId=138352&objAction=browse&sort=name Technical Committee ISO/TC 154], Processes, data elements and documents in commerce, industry and administration.
* [http://isotc.iso.org/livelink/livelink/fetch/2000/2122/138351/138352/customview.html?func=ll&objId=138352&objAction=browse&sort=name Technical Committee ISO/TC 154], Processes, data elements and documents in commerce, industry and administration.
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* [http://www.cl.cam.ac.uk/~mgk25/iso-time.html ISO 8601 summary by Markus Kuhn]
 
* [http://www.phys.uu.nl/~vgent/calendar/isocalendar.htm The Mathematics of the ISO 8601 Calendar]
* [http://www.phys.uu.nl/~vgent/calendar/isocalendar.htm The Mathematics of the ISO 8601 Calendar]
* [http://www.personal.ecu.edu/mccartyr/isowdcal.html Current date in '''week date''' and '''ordinal date''' format]
* [http://www.personal.ecu.edu/mccartyr/isowdcal.html Current date in '''week date''' and '''ordinal date''' format]
* [http://www.dmoz.org/Science/Reference/Standards/Individual_Standards/ISO_8601/ ISO 8601 at the Open Directory Project]
* [http://www.dmoz.org/Science/Reference/Standards/Individual_Standards/ISO_8601/ ISO 8601 at the Open Directory Project]
* [http://www.w3.org/TR/NOTE-datetime W3C Specification about UTC Date and Time] and IETF Internet standard <nowiki>RFC 3339</nowiki>, based on ISO 8601
* [http://www.w3.org/TR/NOTE-datetime W3C Specification about UTC Date and Time] and IETF Internet standard <nowiki>RFC 3339</nowiki>, based on ISO 8601
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* StackOverflow: [http://stackoverflow.com/questions/tagged/iso-8601 iso-8601 tag] - questions about iso-8601 as related to JavaScript, PHP, MySQL and other programming languages and technologies.
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==Related pages==
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*[[datetime-design-pattern]]
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*[[date-design-pattern]]
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*[[abbr-design-pattern]]

Current revision


The International Standards Organisation's standard, number 8601 is an international standard for date and time representations. It is used for all date-time representations in microformats, as well as a number of other formats (HTML5 <time> element & datetime attribute, XML Schema Datatypes, RDF, Atom).

iso_8601.png

Image: XKCD

In addition, ISO 8601 dates in particular are the most globally unambiguously human readable/writeable date format and thus should always be used on the (world wide) web.

Overview

The following are good prose overviews of ISO 8601:

Microformats

microformats in general use a subset of ISO8601 - preferring uses which are more human readable (requiring hyphens in dates, and colons in times).

All date-time properties in microformats use ISO8601 values. E.g.

Contents

HTML5

HTML5 uses both a subset of ISO 8601 for dates, times, durations for the <time> element, as well as an extended (and more human friendly) duration format.

RFC 3339

RFC 3339 defines a profile of ISO 8601 for the use in Internet protocols and standards.

ISO 8601 implementations in programming libraries

to do! document more implementations.

FAQ

Why hyphens in dates

Q: Must I use the hyphens?[1]

A: You should always use hyphens in ISO 8601 dates because that makes them more readable, and thus more human friendly.

Also, using hyphens helps clearly distinguish different uses for different granularities of dates, e.g.:

Issues

None currently.

Resolved issues: iso-8601-issues-resolved.

See also

Related pages

ISO 8601 was last modified: Thursday, October 3rd, 2013

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