diff options
Diffstat (limited to 'usr.sbin/cron/cron/cron.8')
| -rw-r--r-- | usr.sbin/cron/cron/cron.8 | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/usr.sbin/cron/cron/cron.8 b/usr.sbin/cron/cron/cron.8 index ec66af4..02d3aaf 100644 --- a/usr.sbin/cron/cron/cron.8 +++ b/usr.sbin/cron/cron/cron.8 @@ -26,6 +26,12 @@ .Sh SYNOPSIS .Nm .Oo +.Fl s +.Oc +.Oo +.Fl o +.Oc +.Oo .Fl x .Ar debugflag Ns Op , Ns Ar ... .Oc @@ -71,6 +77,51 @@ need not be restarted whenever a crontab file is modified. Note that the .Xr crontab 1 command updates the modtime of the spool directory whenever it changes a crontab. +.Pp +Available options: +.Bl -tag -width indent +.It Fl s +Enable special handling of situations when the GMT offset of the local +timezone changes, such as the switches between the standard time and +daylight saving time. +.Pp +The jobs run during the GMT offset changes time as +intuitively expected. If a job falls into a time interval that disappears +(for example, during the switch from +standard time) to daylight saving time or is +duplicated (for example, during the reverse switch), then it's handled +in one of two ways: +.Pp +The first case is for the jobs that run every at hour of a time interval +overlapping with the disappearing or duplicated interval. +In other words, if the job had run within one hour before the GMT offset change +(and cron was not restarted nor the +.Xr crontab 5 +changed after that) +or would run after the change at the next hour. +They work as always, skip the skipped time or run in the added +time as usual. +.Pp +The second case is for the jobs that run less frequently. +They are executed exactly once, they are not skipped nor +executed twice (unless cron is restarted or the user's +.Xr crontab 5 +is changed during such a time interval). If an interval disappears +due to the GMT offset change, such jobs are +executed at the same absolute point of time as they would be in the +old time zone. For example, if exactly one hour disappears, this +point would be during the next hour at the first minute that is +specified for them in +.Xr crontab 5 . +.It Fl o +Disable the special handling of situations when the GMT offset of the local +timezone changes, to be compatible with the old (default) behavior. +If both options +.Fl o +and +.Fl s +are specified, the option specified last wins. +.El .Sh SEE ALSO .Xr crontab 1 , .Xr crontab 5 |
