What is a cron job?
Commands a computer runs by itself on a schedule you set, like a report every Monday or a backup every night.
Send a report every Monday. Back up the database every night at two. Developers don't do these by hand. They use cron.
What it is
Cron is a scheduler built into Unix-like systems, like Linux and macOS. A cron job is a command it runs automatically, on a schedule you set.
How it works
Each job is one line in a file called a crontab: five time fields, then the command. The fields are minute, hour, day of the month, month, and day of the week. A star means every. So 0 2 * * * means two in the morning, every day. Kubernetes and GitHub Actions use the same format.
Why it matters
Reports, cleanups, reminders and backups can all run themselves. Just make sure someone hears about it when a job fails.
