systemd Timers

Status: draft · Confidence: low (0.43) · Basis: verified_sources

Quality notes: generic_source_homepage, no_verified_sources, partial_source_verification

## TL;DR

systemd timers are the modern replacement for cron, providing calendar and monotonic event scheduling with better logging, randomization, and dependency management. Timer unit triggers a matching service unit. `systemctl list-timers` shows all active timers.

## Core Explanation

Timer types: OnCalendar (specific times, like cron: `*-*-* 02:00:00` = daily 2AM), OnBootSec (after boot), OnUnitActiveSec (after service last ran). `RandomizedDelaySec` spreads load (avoid thundering herd). Persistent: `Persistent=true` catches up missed runs (like anacron). Accuracy: `AccuracySec` trades precision for power saving (default 1min).

## Further Reading

- [systemd.timer Documentation](undefined)

## Related Articles

- [Systemd](../systemd.md)