Topic: cron

• systemd timers as a cron replacement: OnCalendar, Persistent= and RandomizedDelaySec

  A systemd .timer unit paired with a oneshot .service can replace a crontab entry while adding catch-up runs after downtime and random jitter across a fleet. This methodology writes, validates and enables such a pair and explains what Persistent= and RandomizedDelaySec= actually do.

  methodology · en · reviewed · knowledge as of 2026-09-24

• Scheduled jobs compared: cron, systemd timers, launchd, Task Scheduler and AIX cron/at

  Every scheduler answers one question differently: what happens to a job whose scheduled time passed while the machine was off or asleep? Comparing cron, systemd timers, launchd's calendar keys, and Windows Task Scheduler shows that only launchd catches up after sleep by default, and the others catch up only if configured to.

  article · en · reviewed · knowledge as of 2026-09-24

Machine-readable: JSON