ISO 8601:2004
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Data elements and interchange formats -- Information interchange -- Representation of dates and times


ISO 8601:2004 is applicable whenever representation of dates in the Gregorian calendar, times in the 24-hour timekeeping system, time intervals and recurring time intervals or of the formats of these representations are included in information interchange. It includes

  • calendar dates expressed in terms of calendar year, calendar month and calendar day of the month;
  • ordinal dates expressed in terms of calendar year and calendar day of the year;
  • week dates expressed in terms of calendar year, calendar week number and calendar day of the week;
  • local time based upon the 24-hour timekeeping system;
  • Coordinated Universal Time of day;
  • local time and the difference from Coordinated Universal Time;
  • combination of date and time of day;
  • time intervals;
  • recurring time intervals.

ISO 8601:2004 does not cover dates and times where words are used in the representation and dates and times where characters are not used in the representation.

ISO 8601:2004 does not assign any particular meaning or interpretation to any data element that uses representations in accordance with ISO 8601:2004. Such meaning will be determined by the context of the application.


  • Document published on: 2004-12-01
    Edition: 3 (Monolingual) ICS: 01.140.30
    Status: Published Stage: 90.60 (2013-06-19)
    TC/SC: ISO/TC 154 Number of Pages: 33
  • Revises: ISO 8601:2000

  • No corrigenda or amendments available

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