File: coreutils.info,  Node: Time zone items,  Next: Combined date and time of day items,  Prev: Time of day items,  Up: Date input formats

29.4 Time zone items
====================

A “time zone item” specifies an international time zone, indicated by a
small set of letters, e.g., ‘UTC’ or ‘Z’ for Coordinated Universal Time.
Any included periods are ignored.  By following a non-daylight-saving
time zone by the string ‘DST’ in a separate word (that is, separated by
some white space), the corresponding daylight saving time zone may be
specified.  Alternatively, a non-daylight-saving time zone can be
followed by a time zone correction, to add the two values.  This is
normally done only for ‘UTC’; for example, ‘UTC+05:30’ is equivalent to
‘+05:30’.

   Time zone items other than ‘UTC’ and ‘Z’ are obsolescent and are not
recommended, because they are ambiguous; for example, ‘EST’ has a
different meaning in Australia than in the United States, and ‘A’ has
different meaning as a military time zone than as an obsolete RFC 822
time zone.  Instead, it’s better to use unambiguous numeric time zone
corrections like ‘-0500’, as described in the previous section.

   If neither a time zone item nor a time zone correction is supplied,
timestamps are interpreted using the rules of the default time zone
(*note Specifying time zone rules::).