cron Command

Cron Job Structure

┌───────────────────── # Minute (0 - 59)
│ ┌─────────────────── # Hour (0 - 23)
│ │ ┌───────────────── # Day of Month (1 - 31)
│ │ │ ┌─────────────── # Month (1 - 12)
│ │ │ │ ┌───────────── # Day of Week (0 - 6) (Sunday to Saturday)
│ │ │ │ │
│ │ │ │ │
* * * * * <username> <command-to-execute>

Examples:
0 0 1,15 * * command : Run at midnight of 1,15 of every month
*/10 * * * * command : Run every 10 minutes
0 0-5 * * * command : Run every day every hour between midnight and 5

View Cron Jobs

crontab -l
crontab -u <username> -l

Edit/ Add Cron Jobs

crontab -e
crontab -u <username> -e
crontab <filename> # Add cron Jobs from a file

Delete Cron Jobs

crontab -r

INFO

• For cron jobs of the root user add “sudo” before the command
• Cron jobs are saved in /etc under the folders /cron.d, /cron.hourly, /cron.daily, /cron.monthly, /cron.weekly (Useful if crontab is not present)

Crontab.guru - The cron schedule expression editor