Systemd timer units as a modern alternative to cron.
low risk
Systemd timers replace cron for scheduled tasks, offering dependency management, precise logging via journald, and missed-run catch-up (Persistent=true). A timer unit (.timer) pairs with a service unit (.service) that defines what to run.
systemctl list-timers --allList all timers and their next trigger time · explain & risk-check →systemctl status backup.timerCheck status of a specific timer · explain & risk-check →systemctl enable --now backup.timerEnable and start a timer immediately · explain & risk-check →journalctl -u backup.serviceView logs of the timer's associated service · explain & risk-check →systemd-analyze calendar 'Mon *-*-* 02:00:00'Test a calendar expression · explain & risk-check →Use `systemd-analyze calendar 'your-expression'` to validate timer calendar expressions before deploying — shows next 10 trigger times, saving debugging time.
Reference text is hand-written and may be incomplete — check man systemd for your version. Test destructive commands on a non-production system first.