coreutils: Time zone items

1 
1 29.4 Time zone items
1 ====================
1 
1 A “time zone item” specifies an international time zone, indicated by a
1 small set of letters, e.g., ‘UTC’ or ‘Z’ for Coordinated Universal Time.
1 Any included periods are ignored.  By following a non-daylight-saving
1 time zone by the string ‘DST’ in a separate word (that is, separated by
1 some white space), the corresponding daylight saving time zone may be
1 specified.  Alternatively, a non-daylight-saving time zone can be
1 followed by a time zone correction, to add the two values.  This is
1 normally done only for ‘UTC’; for example, ‘UTC+05:30’ is equivalent to
1 ‘+05:30’.
1 
1    Time zone items other than ‘UTC’ and ‘Z’ are obsolescent and are not
1 recommended, because they are ambiguous; for example, ‘EST’ has a
1 different meaning in Australia than in the United States.  Instead, it’s
1 better to use unambiguous numeric time zone corrections like ‘-0500’, as
1 described in the previous section.
1 
1    If neither a time zone item nor a time zone correction is supplied,
1 timestamps are interpreted using the rules of the default time zone
1 (⇒Specifying time zone rules).
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