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Cron expressions: schedule jobs with confidence

Understand five-field cron syntax and avoid timezone surprises in production.

2026-05-25 · 5 min read

Cron schedules recurring tasks on Unix-like systems and in orchestrators such as Kubernetes CronJob. A typical expression has five fields: minute, hour, day of month, month, day of week.

Examples

Always confirm whether your platform uses UTC or local time. Daylight saving shifts can cause duplicate or skipped runs if misunderstood.

  • */15 * * * * — every 15 minutes
  • 0 2 * * * — daily at 02:00
  • 0 9 * * 1 — Mondays at 09:00

Testing before deploy

Preview the next N run times with a cron helper before committing to production. Document the intended human meaning next to the expression in your infrastructure repo.

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