whatis systemd-timer
systemd Timer
Also known as: .timer, OnCalendar
A systemd unit that activates a service on a schedule or after a delay, a modern alternative to cron jobs.
What Is a systemd Timer?
A .timer unit is paired with a .service of the same name. OnCalendar=daily or OnCalendar=Mon *-*-* 03:00 sets a wall-clock schedule, while OnBootSec= and OnUnitActiveSec= set relative ones.
Timers log output to the journal, can catch up on runs missed while the machine was off with Persistent=true, and support randomized delays. systemctl list-timers shows when each one fires next.
Example
[Timer]
OnCalendar=*-*-* 03:00
Persistent=trueLearn more about systemd Timer
- Scheduling Tasks with systemd Timers systemd timers are the modern alternative to cron for scheduling tasks on Linux. They offer better logging, dependency support, randomisation, and integration with the rest of the systemd ecosystem.
- cron vs systemd Timers: Which to Use Why a cron job that fails silently is the default behaviour, what timers give you that cron cannot, and when cron is still the right answer.
Related tools
- systemd Timer Builder Generate paired .timer and .service units with OnCalendar schedules, persistence, and randomised delay.
- Crontab Generator Build cron schedule expressions visually, with plain-English previews of when your job will run.