Enable time jitter.
Prior to executing commands,
will sleep a random number of seconds in the range from 0 to
This will not affect superuser jobs (see
A value for
must be between 0 and 60 inclusive.
Default is 0, which effectively disables time jitter.
This option can help to smooth down system load spikes during moments when a lot of jobs are likely to start at once, e.g., at the beginning of the first minute of each hour.
|Enable time jitter for superuser jobs. The same as -j except that it will affect jobs run by the superuser only.|
|Overrides the default recipient for cron mail. Each crontab(5) without MAILTO explicitly set will send mail to the mailto mailbox. Sending mail will be disabled by default if mailto set to a null string, usually specified in a shell as or "".|
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.
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 is handled in one of two ways:
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 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.
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 users 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 crontab(5).
|-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 -o and -s are specified, the option specified last wins.|
|-x debugflag [,...]|
Enable writing of debugging information to standard output.
One or more of the following comma separated
identifiers must be specified:
|bit||currently not used|
|ext||make the other debug flags more verbose|
|load||be verbose when loading crontab files|
|misc||be verbose about miscellaneous one-off events|
|pars||be verbose about parsing individual crontab lines|
|proc||be verbose about the state of the process, including all of its offspring|
|sch||be verbose when iterating through the scheduling algorithms|
|test||trace through the execution, but do not perform any actions|
/etc/crontab System crontab file /etc/pam.d/cron pam.conf(5) configuration file for cron /var/cron/tabs Directory for personal crontab files
.An Paul Vixie Aq email@example.com