Cron Format
* * * * * command to be executedTable of Contents
Practical Examples
* * * * * /opt/backup.sh*/7 * * * * /opt/ping.sh0 */6 * * * /opt/emptytrash.sh20 14 * * * /opt/upgrade5 9 * 4 * /opt/upgrade20 14 * * 7 /opt/update.sh6 11 * * 3 /opt/upgrade.sh0 22 * * 1-5 /opt/upgrade.sh0 0 * * 2 /opt/upgrade.sh10 8 * * 4L /opt/monitor.sh15 0 * * 4#2 /opt/upgrade0 0 0 1 * * /opt/backup.sh0 0 0 1 1 * /opt/backup.sh5 12 * * 6 /opt/emptytrash.sh@reboot /opt/backup.shSpecial Strings
Execute once at system startup (non-standard)
Execute once every hour, same as 0 * * * * (non-standard)
Execute once per day, same as 0 0 * * * (non-standard)
Same as @daily (non-standard)
Execute once every week, same as 0 0 * * 0 (non-standard)
Execute once per month, same as 0 0 1 * * (non-standard)
Execute once per year, same as 0 0 1 1 * (non-standard)
Same as @yearly (non-standard)
Crontab Commands
Edit or create a crontab file
$ crontab -eTip: Check our Linux commands cheatsheet for more text editor options.
Display the crontab file
$ crontab -lRemove the crontab file
$ crontab -rDisplay another user's crontab file
$ crontab -u username -lEdit another user's crontab file
$ crontab -u username -eDisplay last time you edited your crontab file
$ crontab -vSpecial Characters
* Asterisk (*)
Represents all potential values in a field. For example, an asterisk in the Minute column means"every minute".
- Hyphen (-)
Used to determine a range of values. For example, write 1-5 in the Weekday field to schedule a task from Monday through Friday.
/ Slash (/)
Used to split a value. For instance, */5 in the Hours field signifies"every 5 hours".
, Comma (,)
Used to list numerous values. Writing 1,5 in the Day of the week field schedules the task to be executed every Monday and Friday.
L Last (L)
Used in the month and weekday fields. Writing 6L in the day-of-week field, for example, signifies"the last Saturday of the month".
W Weekday (W)
Used to get the closest weekday from a given time. For instance, entering 1W in the day-of-month field will execute the command on the following Monday (the 3rd).
# Hash (#)
Only valid in the Day-of-week field, followed by a number between 1 and 5. For example, 5#2 denotes"the second Friday" of a given month.
? Question mark (?)
Can be used instead of'*' in the Day of Month and Day of Week fields. Use this operator to enter"no specified value" for the"day of the month" and"day of the week" fields.
Related Cheatsheets
Enhance your automation workflow with these complementary guides
Linux Commands
Essential commands for your cron job scripts
Process Management
Monitor and manage background processes
Linux Networking
Network automation and monitoring tasks
Docker
Schedule containerized tasks and deployments
Git Commands
Version control for automation scripts
Log Parsing
Analyze cron job output and system logs
