crontab

• list all cron jobs
  • crontab -l
• edit cron jobs
  • crontab -e

# ┌───────────── minute (0 - 59)
# │ ┌───────────── hour (0 - 23)
# │ │ ┌───────────── day of month (1 - 31)
# │ │ │ ┌───────────── month (1 - 12)
# │ │ │ │ ┌───────────── day of week (0 - 6) (Sun to Sat;
# │ │ │ │ │                              7 is also Sunday on some systems)
# * * * * *  command_to_execute

e.g. At 12:00 on every 7th day-of-month from 1 through 31. (1, 8, 15, 22, 29)
→ basically weekly at noon

0 12 1-31/7 * * echo henlo 

ref:

• https://crontab.guru/