PatternCron
Nightly at 02:30
The backup-window classic: once a day at 02:30 — plus the daylight-saving trap that makes 02:30 a risky hour to pick.
Last updated
In plain English
- Fires once per day at 02:30
- 365 runs per year — minus DST surprises
Why it’s written this way
Minute 30, hour 2, everything else unconstrained: one run per day at 02:30. Off-peak hours are the convention for backups and batch jobs because they compete least with real traffic.
Putting the minute at 30 rather than 0 also dodges the top-of-the-hour spike, when everyone else's nightly jobs fire.
Edge cases to know
- →In timezones with daylight saving, the 02:00–03:00 hour is the one that gets skipped or repeated. A 02:30 job can run zero times or twice on transition nights — schedule in UTC, or pick an hour outside the shift window.
- →Long jobs can overlap the next night's run — guard with a lockfile (flock) if a second copy would corrupt state.
- →Cron email on failure only works if MAILTO and a mailer are configured; otherwise failures are silent.