Editing ISO 8601 (section)

==History==
The first edition of the ISO&nbsp;8601 standard was published as ''ISO&nbsp;8601:1988'' in 1988. It unified and replaced a number of older ISO standards on various aspects of date and time notation: [[ISO 2014]], [[ISO 2015]], [[ISO 2711]], [[ISO 3307]], and [[ISO 4031]].<ref name="doc2004">{{Citation |title=ISO 8601:2004(E) |date=2004-12-01 |publisher=[[International Organization for Standardization|ISO]] |quote=Annex&nbsp;A: ... From that concept representations of all other date and time values were logically derived; thus, ISO&nbsp;2014, ISO&nbsp;3307 and ISO&nbsp;4031 have been superseded. ... Identification of a particular date by means of ordinal dates (ISO&nbsp;2711) and by means of the week numbering system (ISO&nbsp;2015) were alternative methods that the basic concept of this International Standard could also encompass; thus, ISO&nbsp;2015 and ISO&nbsp;2711 have now been superseded.}}</ref> It has been superseded by a second edition ''ISO&nbsp;8601:2000'' in 2000, by a third edition ''ISO&nbsp;8601:2004'' published on 1 December 2004, and withdrawn and revised by ''ISO&nbsp;8601-1:2019'' and ''ISO&nbsp;8601-2:2019'' on 25 February 2019. ISO&nbsp;8601 was prepared by,<ref>{{Cite book |title=ISO 8601:2004(E) |date=2004-12-01 |publisher=[[International Organization for Standardization|ISO]] |at=p.&nbsp;iv Foreword}}</ref> and is under the direct responsibility of, [[List of ISO technical committees|ISO Technical Committee]] TC 154.<ref>{{Cite web |title=TC 154 Processes, data elements and documents in commerce, industry and administration |url=http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=53186&published=on |url-status=live |archive-url=https://web.archive.org/web/20160525114524/http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=53186&published=on |archive-date=2016-05-25 |access-date=2014-08-16 |publisher=ISO |department=Technical committees}}</ref>

ISO&nbsp;2014, though superseded, is the standard that originally introduced the all-numeric date notation in [[Significant figures|most-to-least-significant]] order {{nowrap|[YYYY]-[MM]-[DD]}}. The ISO week numbering system was introduced in ISO&nbsp;2015, and the identification of days by ordinal dates was originally defined in ISO&nbsp;2711.

Issued in February 2019,<ref name=":1">{{Cite web |date=26 August 2019 |title=Introduction to the new ISO 8601-1 and ISO 8601-2 |url=https://www.isotc154.org/posts/2019-08-27-introduction-to-the-new-8601/ |website=ISO/TC 154}}</ref> the fourth revision of the standard ISO&nbsp;8601-1:2019 represents slightly updated contents of the previous ISO&nbsp;8601:2004 standard,<ref>{{Cite web |title=ISO/DIS 8601-1:2016-10-26 |url=https://www.loc.gov/standards/datetime/ISO_DIS%208601-1.pdf |archive-url=https://web.archive.org/web/20171019211402/https://www.loc.gov/standards/datetime/ISO_DIS%208601-1.pdf |archive-date=2017-10-19 |website=[[Library of Congress]]}}</ref><ref name=":0">{{Cite web |title=German draft ''E DIN ISO 8601-1:2017-02 Datenelemente und Austauschformate - Informationsaustausch - Darstellung von Datum und Uhrzeit - Teil 1: Grundlegende Regeln (ISO/DIS 8601-1:2016)'' |url=https://www.din.de/de/mitwirken/normenausschuesse/nia/entwuerfe/wdc-beuth:din21:266843241 |url-status=live |archive-url=https://web.archive.org/web/20171020151006/https://www.din.de/de/mitwirken/normenausschuesse/nia/entwuerfe/wdc-beuth:din21:266843241 |archive-date=2017-10-20 |access-date=2017-10-19 |publisher=DIN-Normenausschuss Informationstechnik und Anwendungen (NIA)}}</ref> whereas the new ISO&nbsp;8601-2:2019 defines various extensions such as uncertainties or parts of the [[#EDTF|Extended Date/Time Format]] (EDTF).<ref name="EDTF_2019_Spec">{{Cite web |date=2019-10-08 |orig-date=2019-02-04, 2014, 2012 |title=Extended Date/Time Format (EDTF) Specification |url=https://www.loc.gov/standards/datetime/ |url-status=live |archive-url=https://web.archive.org/web/20200307193917/https://www.loc.gov/standards/datetime/ |archive-date=2020-03-07 |access-date=2020-03-07 |publisher=[[The Library of Congress]]}}</ref><ref name="EDTF_2019_Background">{{Cite web |date=2019-10-08 |orig-date=2019-03-01 |title=Extended Date/Time Format (EDTF) Background |url=https://www.loc.gov/standards/datetime/background.html |url-status=live |archive-url=https://web.archive.org/web/20200307193911/https://www.loc.gov/standards/datetime/background.html |archive-date=2020-03-07 |access-date=2020-03-07 |publisher=[[The Library of Congress]]}}</ref><ref name="EDTF_2014">{{Cite web |title=Extended Date/Time Format (EDTF) 1.0 2012/2014 |url=https://www.loc.gov/standards/datetime/pre-submission.html |archive-url=https://web.archive.org/web/20170715194139/http://www.loc.gov/standards/datetime/pre-submission.html |archive-date=2017-07-15 |access-date=2017-07-15 |series=Draft Submission |publisher=[[The Library of Congress]]}}</ref><ref>{{Cite web |title=ISO/WD 8601-2:2016-02-16 |url=https://www.loc.gov/standards/datetime/iso-tc154-wg5_n0039_iso_wd_8601-2_2016-02-16.pdf |archive-url=https://web.archive.org/web/20171019222039/https://www.loc.gov/standards/datetime/iso-tc154-wg5_n0039_iso_wd_8601-2_2016-02-16.pdf |archive-date=2017-10-19 |website=[[Library of Congress]]}}</ref><ref>{{Cite web |title=ISO/DIS 8601-2:2016-10-26 |url=https://www.loc.gov/standards/datetime/ISO_DIS%208601-2.pdf |archive-url=https://web.archive.org/web/20171020000043/https://www.loc.gov/standards/datetime/ISO_DIS%208601-2.pdf |archive-date=2017-10-20 |website=[[Library of Congress]]}}</ref><ref>{{Cite web |title=German draft ''E DIN ISO 8601-2:2017-02 Datenelemente und Austauschformate - Informationsaustausch - Darstellung von Datum und Uhrzeit - Teil 2: Erweiterungen (ISO/DIS 8601-2:2016)'' |url=https://www.din.de/de/mitwirken/normenausschuesse/nia/entwuerfe/wdc-beuth:din21:266843381 |url-status=live |archive-url=https://web.archive.org/web/20171019230355/https://www.din.de/de/mitwirken/normenausschuesse/nia/entwuerfe/wdc-beuth:din21:266843381 |archive-date=2017-10-19 |access-date=2017-10-19 |publisher=DIN-Normenausschuss Informationstechnik und Anwendungen (NIA)}}</ref>

An amendment to ISO 8601-1 was published in October 2022 featuring minor technical clarifications and attempts to remove ambiguities in definitions. The most significant change, however, was the reintroduction of the "24:00:00" format to refer to the instant at the ''end'' of a calendar day.

An amendment to ISO 8601-2 was published in January 2025.

{| class="wikitable sortable"
|+ History of published editions and amendments
! Name || Description
|-
| ISO 8601:1988 || Data elements and interchange formats — Information interchange — Representation of dates and times
|-
| ISO 8601:1988/COR 1:1991 || Data elements and interchange formats — Information interchange — Representation of dates and times — Technical Corrigendum 1
|-
| ISO 8601:2000 || Data elements and interchange formats — Information interchange — Representation of dates and times
|-
| ISO 8601:2004 || Data elements and interchange formats — Information interchange — Representation of dates and times
|-
| ISO 8601-1:2019 || Date and time — Representations for information interchange — Part 1: Basic rules
|-
| ISO 8601-2:2019 || Date and time — Representations for information interchange — Part 2: Extensions
|-
| ISO 8601-1:2019/Amd 1:2022 || Date and time — Representations for information interchange — Part 1: Basic rules — Amendment 1: Technical corrections
|-
| ISO 8601-2:2019/Amd 1:2025 || Date and time — Representations for information interchange — Part 2: Extensions — Amendment 1: Canonical expressions, extensions to time scale components and date time arithmetic
|}