Editing ISO 8601 (section)

===Calendar dates===
{| class="infobox" style="text-align:center; width:23em"
| {{nowrap|YYYY-MM-DD}} ||''or''|| YYYYMMDD
|-
| {{nowrap|YYYY-MM}}
| colspan="2"| (''but not'' YYYYMM)
|-
| colspan=3 | '''Only allowed in the (now superseded) 2000 version:'''<ref name="datewithoutyear">last in ISO 8601:2000, in use by {{cite IETF
 |rfc=6350|section=4.3.1
 |title=vCard Format Specification |sectionname=DATE
 |access-date=2021-01-21
 |date=August 2011
 |publisher=[[Internet Engineering Task Force|IETF]]
 |quote=Truncated representation, as specified in [ISO.8601.2000], Sections 5.2.1.3 d), e), and f), is permitted.
 |last1=Perreault
 |first1=S.
 }}, although removed in ISO 8601:2004</ref>
|-
| {{nowrap|YY-MM-DD}} ||''or''|| YYMMDD
|-
| {{nowrap|-YY-MM}} ||''or''|| -YYMM
|-
| {{nowrap|--MM-DD}} ||''or''|| --MMDD
|-
| {{nowrap|--MM}}
|-
| {{nowrap|---DD}}
|}

Calendar date representations are in the form shown in the adjacent box. [YYYY] indicates a four-digit year, 0000 through 9999. [MM] indicates a two-digit month of the year, 01 through 12. [DD] indicates a two-digit day of that month, 01 through 31. For example, "5 April 1981" may be represented as either {{nowrap|"1981-04-05"}}<ref name=isofaqtnd/> in the ''extended format'' or "19810405" in the ''basic format''.

The standard also allows for calendar dates to be written with reduced precision. For example, one may write {{nowrap|"1981-04"}} to mean "1981 April". One may simply write "1981" to refer to that year, "198" to refer to the [[decade]] from 1980 to 1989 inclusive, or "19" to refer to the [[century]] from 1900 to 1999 inclusive. Although the standard allows both the {{nowrap|"YYYY-MM-DD"}} and YYYYMMDD formats for complete calendar date representations, if the day [DD] is omitted then only the {{nowrap|YYYY-MM}} format is allowed. By disallowing dates of the form YYYYMM, the standard avoids confusion with the [[#Truncated representations|truncated representation]]<ref name="iso8601amd1" /><ref name="doc2004" /> YYMMDD (still often used). The 2000 version also allowed writing the truncation {{nowrap|"--04-05"}} to mean "April 5"<ref>{{cite IETF
 |rfc=6350|section=4.3.1
 |title=vCard Format Specification |sectionname=DATE
 |access-date=2016-06-29
 |date=August 2011
 |publisher=[[Internet Engineering Task Force|IETF]]
 |quote=Truncated representation, as specified in [ISO.8601.2000], Sections 5.2.1.3 d), e), and f), is permitted.
 |last1=Perreault
 |first1=S.
 }}</ref> but the 2004 version does not allow omitting the year when a month is present.

Examples:

* 7 January 2000 can be written as "2000-01-07" or "20000107"