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;
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.