@c GNU date syntax documentation
@c Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
-@c 2003, 2004, 2005 Free Software Foundation, Inc.
+@c 2003, 2004, 2005, 2006 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
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}
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}.