Time Utilities

Cron Expression

Parse cron expressions to show next run times, or generate cron from options.

✨AI Generate (Cloudflare Workers AI)
min: 0 min · hour: 9 hour · day: 31 values · month: 12 values · weekday: 7 values
Next 5 runs:
  • Aug 31, 2026, 09:00:00
  • Sep 1, 2026, 09:00:00
  • Sep 2, 2026, 09:00:00
  • Sep 3, 2026, 09:00:00
  • Sep 4, 2026, 09:00:00

What is Cron Expression?

Cron expressions define schedules for recurring tasks. This tool helps create, parse, and validate cron expressions.

Cron Format

  • Standard: minute hour day month weekday
  • Extended: second minute hour day month weekday

Use Cases

  • Scheduled jobs configuration
  • CI/CD pipeline scheduling
  • Backup automation

Frequently Asked Questions

What do the five fields mean?
Minute, hour, day-of-month, month, day-of-week. */10 in the minute field means "every 10 minutes". This tool also accepts a 6-field form with seconds, common in Quartz and Spring.
Why does my job run at a different time than expected?
Cron is evaluated in the server’s local timezone. 09:00 in UTC+8 fires at 01:00 UTC. Confirm the timezone of the machine or scheduler, then read the expression in that zone.
What is the difference between * and ? in the day fields?
In flavors that support both (Quartz), ? means "unconstrained" and lets you restrict only one of day-of-month / day-of-week. In standard five-field cron, restrict one field and leave the other as *.