What methods can be used to organize automatic script execution in Linux at a specified time or on a schedule?

In Linux, the most commonly used tools for automatically running scripts at a specified time or on a schedule are:

1. cron — the most widespread method. Using the command crontab -e, you can set a schedule for running scripts. The record format includes minutes, hours, days of the month, months, and days of the week.

   Example of a record to run a script every day at 3:30:

   30 3 * * * /path/to/script.sh
   

2. systemd timers — a modern method if systemd is used. It allows creating timers that start services according to a schedule.

3. at — for a one-time task execution at a specified time.

4. Scripts in directories like /etc/cron.daily/, /etc/cron.hourly/, etc. — for periodic execution without editing crontab.

Thus, for regular tasks, cron is usually used, and for more complex scenarios — systemd timers.