Crontab is a file containing instructions for the cron daemon. It is a job scheduler where you add commands to be executed at defined periods.
Edit existing crontab file, or make new one if it doesn’t exist:
List of cronjobs , display crontab file contents:
service cron reload
(not necessary since the system will check periodically for crontab changes and apply them)
Removes the crontab file:
Time format in crontab
|min (0-59)||hour (0-23)||day of the month (1-31)||month (1-12)||day of the week (0-6)|
|Sunday = 0|
* is a wildcard, meaning any value from the given range
/ adds a step value
*/5 * * * *
This will be executed every 5 minutes.
0 18 * * 1-3
This will be executed at 18:00h on every day of the week from Monday to Wednesday.