crontab.conf
# ┌───────────── min (0 - 59)
# │ ┌────────────── hour (0 - 23)
# │ │ ┌─────────────── day of month (1 - 31)
# │ │ │ ┌──────────────── month (1 - 12)
# │ │ │ │ ┌───────────────── day of week (0 - 6) (0 to 6 are Sunday to Saturday, or use names; 7 is Sunday, the same as 0)
# │ │ │ │ │
# │ │ │ │ │
# * * * * * command to execute
15 03 * * 0 ~/bubbly/bubbly_renew-ssl.sh -d example.com -d www.example.com >> ~/bubbly/cron.log