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Diffstat (limited to 'doc/coreutils.texi')
| -rw-r--r-- | doc/coreutils.texi | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 73b650e84..94ece47ce 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -10472,6 +10472,7 @@ GNU extension). Note that this value is the number of seconds between the epoch and the current date as defined by the localtime system call. It isn't changed by the @option{--date} option. +For examples, @xref{%s-examples}. @item %S second (00@dots{}60). The range is [00@dots{}60], and not [00@dots{}59], in order to accommodate the occasional positive leap second. @@ -10830,6 +10831,7 @@ use @samp{date --rfc}. I just did and saw this: Mon, 25 Mar 1996 23:34:17 -0600 @end example +@anchor{%s-examples} @item To convert a date string to the number of seconds since the epoch (which is 1970-01-01 00:00:00 UTC), use the @option{--date} option with @@ -10866,6 +10868,17 @@ date --date='2000-01-01 UTC' +%s 946684800 @end example +An alternative is to use the @option{--utc} (@option{-u}) option. +Then you may omit @samp{UTC} from the date string. Although this +produces the same result for @samp{%s} and many other format sequences, +with a time zone offset different from zero, it would give a different +result for zone-dependent formats like @samp{%z}. + +@example +date -u --date=2000-01-01 +%s +946684800 +@end example + To convert such an unwieldy number of seconds back to a more readable form, use a command like this: @@ -10875,6 +10888,13 @@ date -d '1970-01-01 UTC 946684800 seconds' +"%Y-%m-%d %T %z" 1999-12-31 19:00:00 -0500 @end smallexample +Often it is better to output UTC-relative date and time: + +@smallexample +date -u -d '1970-01-01 946684800 seconds' +"%Y-%m-%d %T %z" +2000-01-01 00:00:00 +0000 +@end smallexample + @end itemize |