Skip to content
yutils
Cron Expression Parser
Example

Input (pick 5 fields)

Minute: 0
Hour: 9
Day: *
Month: *
Weekday: 1-5

Output

0 9 * * 1-5

Human-readable: At 09:00 AM, Monday through Friday

Next 5 runs:
  2026-05-14 09:00
  2026-05-15 09:00
  2026-05-18 09:00
  2026-05-19 09:00
  2026-05-20 09:00

Note

The composed expression is run through cronstrue (text) and cron-parser (firing times). Output is fully compatible with the Cron Expression Parser tool.

Usage / FAQ

When to use

  • Compose Kubernetes CronJob or GitHub Actions schedule expressions visually
  • Unpack macros like @hourly / @daily into explicit fields
  • Verify field-by-field intent before committing a complex cron
  • Fill in cron input forms for AWS EventBridge, Cloud Scheduler, etc.
  • Learn cron by clicking presets and watching the result update

FAQ

Q.Is Quartz 6-field (with seconds) supported?
A.Standard 5 fields only (minute hour day month weekday). Quartz / Spring Schedule's 6-field is accepted by cron-parser in a different mode, but the builder UI doesn't expose it. Same for 7+ field variants.
Q.What about extensions like `L` (last day) or `#` (nth weekday)?
A.Type them into the free input — the builder doesn't ship presets for every extension, but the value is passed to cron-parser as-is. Non-standard syntax may surface as an error in the next-runs preview.
Q.How do I use the result?
A.Copy the expression and paste into crontab, a k8s spec, a GitHub Actions schedule, etc. The human-readable summary and next-5-firings preview confirm the intent before you commit.
Fun facts

  • Unix cron's 5-field notation (minute / hour / day / month / weekday) was created by Brian Kernighan at Bell Labs in 1975. The name 'cron' comes from the Greek χρόνος (chronos, time). 50 years later the syntax is essentially unchanged — a true design lingua franca.

    Wikipedia — cron history

  • Quartz Scheduler (Java) and some BSD crons support a 6- or 7-field format (adding seconds and/or year). With AWS EventBridge and Spring Scheduler adopting the 6-field variant, 'cron expressions differ subtly across systems' became a real compatibility pothole.

    Quartz — Cron syntax

  • Both 0 and 7 mean Sunday in the weekday field — a fossil from two merging conventions: Kernighan's original 0=Sun and ISO's 1=Mon ... 7=Sun. The crontab(5) man page explicitly states '0 or 7 = Sunday' to accept either.

    man crontab(5)

Related guides

Related tools

See all in this category →