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Cron expression explainer

Confirm a schedule before deploying it and understand why a job did or did not run.

minute hour day-of-month month day-of-week

Runs at minutes every 15 of hours 2 on Monday, Tuesday, Wednesday, Thursday, Friday.

  1. Monday, 12 October 2026 at 02:00 (2026-10-12 02:00 UTC)
  2. Monday, 12 October 2026 at 02:15 (2026-10-12 02:15 UTC)
  3. Monday, 12 October 2026 at 02:30 (2026-10-12 02:30 UTC)
  4. Monday, 12 October 2026 at 02:45 (2026-10-12 02:45 UTC)
  5. Tuesday, 13 October 2026 at 02:00 (2026-10-13 02:00 UTC)
  6. Tuesday, 13 October 2026 at 02:15 (2026-10-13 02:15 UTC)
  7. Tuesday, 13 October 2026 at 02:30 (2026-10-13 02:30 UTC)
  8. Tuesday, 13 October 2026 at 02:45 (2026-10-13 02:45 UTC)

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How it measures

  • Standard five-field syntax with ranges, steps, lists, month and weekday names and the common @daily style aliases.
  • When both day-of-month and day-of-week are restricted, a date matches if either matches (Vixie cron semantics).
  • Next runs are evaluated minute by minute in the chosen zone; local times that do not exist on a daylight-saving day are skipped.

Limits

  • Seconds fields, L/W/# modifiers and other extensions are not supported.
  • Your scheduler may interpret edge cases differently; test with its own tooling when in doubt.

Troubleshooting

Job skipped once a year
A schedule at 02:30 local does not exist on the spring-forward day in many zones. Use UTC or a time outside the changeover window.

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