Cron Basics

Edit crontab
crontab -e

List cron jobs
crontab -l

Remove all cron jobs
crontab -r

Edit for specific user
sudo crontab -u username -e

Format
* * * * * command
│ │ │ │ │
│ │ │ │ └─ Day of week (0-7, Sun=0 or 7)
│ │ │ └─── Month (1-12)
│ │ └───── Day of month (1-31)
│ └─────── Hour (0-23)
└───────── Minute (0-59)

Every minute
* * * * * command

Every hour
0 * * * * command

Every day at midnight
0 0 * * * command

Every Sunday at 3am
0 3 * * 0 command

Every 5 minutes
*/5 * * * * command

At reboot
@reboot command

Daily
@daily command

Weekly
@weekly command

Monthly
@monthly command

Yearly
@yearly command