crontab flags & options

-e

Edit the current user's crontab file.

crontab -e

-l

List the current user's crontab entries.

crontab -l

-r

Remove the current user's crontab entirely.

crontab -r

-u

Operate on a specific user's crontab.

crontab -u www-data -l

sudo crontab -u deploy -e

Cron syntax: minute hour day month weekday

Schedule format uses five fields: minute (0-59), hour (0-23), day of month (1-31), month (1-12), weekday (0-7, 0 and 7 are Sunday).

# Every day at 2:30 AM
30 2 * * * /usr/local/bin/backup.sh

# Every Monday at 9 AM
0 9 * * 1 /usr/local/bin/report.sh

# Every 15 minutes
*/15 * * * * /usr/local/bin/health-check.sh

# First day of every month at midnight
0 0 1 * * /usr/local/bin/monthly-cleanup.sh