@c GNU date syntax documentation
-@c Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
-@c 2003, 2004 Free Software Foundation, Inc.
+@c Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
+@c 2004, 2005, 2006, 2009, 2010 Free Software Foundation, Inc.
@c Permission is granted to copy, distribute and/or modify this document
-@c under the terms of the GNU Free Documentation License, Version 1.1 or
+@c under the terms of the GNU Free Documentation License, Version 1.3 or
@c any later version published by the Free Software Foundation; with no
@c Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
@c Texts. A copy of the license is included in the ``GNU Free
Mon Mar 1 00:21:42 UTC 2004
$ TZ=UTC0 date +'%Y-%m-%d %H:%M:%SZ'
2004-03-01 00:21:42Z
-$ date --iso-8601=ns # a GNU extension
-2004-02-29T16:21:42,692722128-0800
+$ date --iso-8601=ns | tr T ' ' # --iso-8601 is a GNU extension.
+2004-02-29 16:21:42,692722128-0800
$ date --rfc-2822 # a GNU extension
Sun, 29 Feb 2004 16:21:42 -0800
$ date +'%Y-%m-%d %H:%M:%S %z' # %z is a GNU extension.
nested. Hyphens not followed by a digit are currently ignored. Leading
zeros on numbers are ignored.
+Invalid dates like @samp{2005-02-29} or times like @samp{24:00} are
+rejected. In the typical case of a host that does not support leap
+seconds, a time like @samp{23:59:60} is rejected even if it
+corresponds to a valid leap second.
+
@node Calendar date items
@section Calendar date items
@samp{.} or @samp{,} and a fraction containing one or more digits.
Alternatively,
@samp{:@var{second}} can be omitted, in which case it is taken to
-be zero.
+be zero. On the rare hosts that support leap seconds, @var{second}
+may be 60.
@findex am @r{in date strings}
@findex pm @r{in date strings}
The time may alternatively be followed by a time zone correction,
expressed as @samp{@var{s}@var{hh}@var{mm}}, where @var{s} is @samp{+}
or @samp{-}, @var{hh} is a number of zone hours and @var{mm} is a number
-of zone minutes. When a time zone correction is given this way, it
+of zone minutes.
+The zone minutes term, @var{mm}, may be omitted, in which case
+the one- or two-digit correction is interpreted as a number of hours.
+You can also separate @var{hh} from @var{mm} with a colon.
+When a time zone correction is given this way, it
forces interpretation of the time relative to
Coordinated Universal Time (@sc{utc}), overriding any previous
-specification for the time zone or the local time zone. The @var{minute}
-part of the time of day may not be elided when a time zone correction
-is used. This is the best way to specify a time zone correction by
-fractional parts of an hour.
+specification for the time zone or the local time zone. For example,
+@samp{+0530} and @samp{+05:30} both stand for the time zone 5.5 hours
+ahead of @sc{utc} (e.g., India).
+This is the best way to
+specify a time zone correction by fractional parts of an hour.
+The maximum zone correction is 24 hours.
Either @samp{am}/@samp{pm} or a time zone correction may be specified,
but not both.
non-daylight-saving time zone by the string @samp{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 @samp{UTC}; for example, @samp{UTC+05:30} is equivalent to
+@samp{+05:30}.
Time zone items other than @samp{UTC} and @samp{Z}
are obsolescent and are not recommended, because they
of seconds with nanosecond subcounts, and can represent all the times
in the known lifetime of the universe to a resolution of 1 nanosecond.
-On most systems, these counts ignore the presence of leap seconds.
-For example, on most systems @samp{@@915148799} represents 1998-12-31
+On most hosts, these counts ignore the presence of leap seconds.
+For example, on most hosts @samp{@@915148799} represents 1998-12-31
23:59:59 @sc{utc}, @samp{@@915148800} represents 1999-01-01 00:00:00
@sc{utc}, and there is no way to represent the intervening leap second
1998-12-31 23:59:60 @sc{utc}.
projects / gnulib.git / blobdiff