cron is a time-based task scheduler that allows developers and system administrators to automate the execution of commands and scripts at specific dates, times, or intervals, down to the minute.

These cron jobs are often used to schedule system updates, perform data backups, send emails, clear log files, and so on.

Installing cron on Linux

To install cron on Linux, you can use the following apt command:

$ sudo apt install cron -y

And launched it as a background job (i.e. daemon) using the service command:

$ sudo service cron start

Note: cron is already included in macOS distributions.

The crontab format

The tasks managed by cron are listed in a file named a crontab, where each line represents a distinct task:

m h dom mon dow cmd

Where: