Cron Expression Builder

Build, validate, and visualize cron schedules. See exactly when your jobs will run.

Presets

0 * * * *

Every hour

What is a cron expression?

A cron expression is a string of five (or six) fields separated by spaces that defines a recurring schedule. Originally from Unix systems, cron expressions are now used across modern infrastructure — from CI/CD pipelines and cloud functions to container orchestration and monitoring systems.

The standard five fields are: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, where 0 is Sunday).

How to use this tool

  1. Click each field (minute, hour, day, month, weekday) to set your schedule
  2. Use the dropdown to select specific values, ranges, or intervals
  3. The expression updates in real time as you make selections
  4. Check the calendar view below to see exactly when your jobs will fire
  5. Copy the expression and paste it into your crontab, GitHub Actions, or scheduler config

Common cron examples

* * * * * — Every minute
*/5 * * * * — Every 5 minutes
0 * * * * — Every hour, on the hour
0 9 * * 1-5 — 9:00 AM on weekdays
0 0 * * 0 — Midnight every Sunday
0 0 1 * * — Midnight on the 1st of every month
30 2 * * 1 — 2:30 AM every Monday

Where cron expressions are used

  • Linux/macOS crontab — System-level scheduled tasks
  • GitHub Actions — on: schedule workflow triggers
  • AWS CloudWatch / Lambda — Scheduled function invocations
  • Kubernetes CronJobs — Scheduled container workloads
  • Cloudflare Workers — Cron Triggers for edge functions

Special characters

* — Any value (wildcard)
, — List separator (e.g. 1,15 = 1st and 15th)
- — Range (e.g. 1-5 = Monday to Friday)
/ — Step (e.g. */10 = every 10 units)

FAQ

Is my data sent to a server?

No. This tool runs entirely in your browser. No data is transmitted or stored.

Does this support 6-field cron (with seconds)?

This tool uses the standard 5-field format. Some systems like Spring and Quartz use a 6th field for seconds — prepend 0 to the expression if you need it.

What timezone does the calendar use?

The calendar preview uses your browser's local timezone. Your actual cron daemon may use UTC — check your system settings.