PTBox

Cron Expression Parser & Schedule Preview

Parse Unix cron expressions, generate a human-readable description, and preview the next 10 scheduled run times. Supports both 5-field standard cron and 6-field (with seconds) Quartz-style expressions.

Standard 5 fields: minute hour day month weekday. Supports *, range a-b, list a,b,c, step */n.

分钟小时星期
*/5****
0-590-231-311-120-6 (0=周日)
Meaning: 每隔 5 分钟

Usage

Cron is a compact syntax for scheduling tasks on Unix systems, also used by Quartz, Airflow, Kubernetes CronJob and many others.

Built on cron-parser and cronstrue — everything runs locally.

Field rules (standard 5 fields)

  • Minute 0–59
  • Hour 0–23
  • Day 1–31
  • Month 1–12 (also JAN-DEC)
  • Weekday 0–6, where 0 = Sunday

Use cases

Verifying a crontab entry

Translate an expression to plain English and confirm it really means "every Monday at 9am".

Configuring scheduling frameworks

Used by Quartz, Airflow, Kubernetes CronJob and many others.

Diagnosing missed runs

Check the next run time to verify it actually matches your expectation.

Learning cron syntax

Plain-English explanation + next 10 run times to build intuition fast.

FAQ

Five-field or six-field cron?

Standard Unix cron is 5 fields (minute hour day month weekday). Quartz / Spring is 6 fields (with seconds first). This tool supports both.

Is weekday 0 Sunday or Monday?

Standard Unix: 0 = Sunday, 1–6 = Monday to Saturday, 7 also = Sunday (compatible).

What if I set both day-of-month and day-of-week?

Most implementations use OR. Quartz requires one of them to be ? meaning 'not specified'.

Which timezone is used?

The browser's local timezone for next-run display. Server cron typically uses the system timezone.

What does */5 mean?

Every 5 units. */5 * * * * = every 5 minutes; 0 */2 * * * = every 2 hours on the hour.

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