Debian commonly uses the date+time format specified in RFC 2822 http://www.ietf.org/rfc/rfc2822.txt for text date+time values in computer-parseable data.

However, there are formats with arguably better properties of both universality and parseability, namely those of ISO 8601 and derivatives like W3CDTF http://www.w3.org/TR/NOTE-datetime and RFC 3339 http://www.ietf.org/rfc/rfc3339.txt specifications.

This page discusses the proposal to change Debian's preferred date+time format to an ISO 8601 profile.

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I don't think there's any reason to use the obsolete RFC 2822 time format in new standards. -- TeemuIkonen

  I think this is a big change and needs to be discussed first. I don't see why you call RFC2822 an obsolete format, it is still used by many different technologies. Debian uses RFC2822 in many other places and I think it's very important to maintain consistency between things. Having one date format for {{{debian/copyright}}} but another date format for {{{debian/changelog}}} (for example) is a Bad Thing. If any change to the standard date format was made, it should be made across the board and preferably use something like W3CDTF. -- NoahSlater

  Hi Teemu, what is the command for genearting ISO 8601 dates? -- CharlesPlessy

In increasing order of precision and verbosity, the commands to get ISO 8601 date+time values (-- BenFinney):

{{{
$ date +'%F'
2008-06-13
$ date +'%FT%T'
2008-06-13T12:06:36
$ date +'%FT%T%:z'
2008-06-13T12:06:43+10:00
}}}

  This is nitpicking, but I really find these dates disgracious (except the first one). How about using {{{date  --rfc-3339=seconds}}} instead if RFC2822 is not acceptable ? It gives an output like {{{2008-06-13 11:33:11+09:00}}}. I unfortunately could not figure out if it is compliant with ISO 8601 or not. --CharlesPlessy

   Indeed using 'T' as a separator between date and time is rather ugly. If space should not be used, then an underscore would perhaps be the most readable alternative. An example datestring would be then {{{2008-06-13_21:06:36+02:00}}}. This would be RFC3339 compatible, since it allows any character to be used as separator. --TeemuIkonen

  AFAICT, the W3CDTF standard is simply a specific profile of ISO 8601 formats. RFC 3339 also specifies one specific ISO 8601 profile. All three (ISO 8601, W3CDTF, RFC 3339) recommend no space separators; the date and time should be separated by a 'T' or 't' character. (RFC 3339 allows using a space separator "for the sake of readability".)  -- BenFinney

  I will reiterate my point that changing the date format for Debian's packaging should be out of scope for Proposals/CopyrightFormat. -- NoahSlater

  Hopefully this separate page can engender a wider discussion. -- BenFinney