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Cron Expression Builder
Build, validate, and understand cron schedules. See plain English explanations and preview when your jobs will run.
Plain English
Quick presets
Cron syntax reference
┌───────────── minute (0-59)
│ ┌───────────── hour (0-23)
│ │ ┌───────────── day of month (1-31)
│ │ │ ┌───────────── month (1-12)
│ │ │ │ ┌───────────── day of week (0-6, Sun-Sat)
│ │ │ │ │
* * * * *
* = any value
*/n = every n units
a-b = range from a to b
a,b = specific values a and b
What is a cron expression?
A cron expression is a string of five fields that represents a schedule for running automated tasks. Used in CI/CD pipelines, cloud schedulers, and automation tools.
The five fields
- •Minute (0-59) — When during the hour
- •Hour (0-23) — When during the day (24-hour format)
- •Day of month (1-31) — Which day of the month
- •Month (1-12) — Which month
- •Day of week (0-6) — Which day (0 = Sunday)
Common use cases
- •Scheduling database backups
- •Running nightly build pipelines
- •Sending periodic reports
- •Cleaning up temporary files
Where cron is used
- •GitHub Actions — Schedule workflows
- •AWS EventBridge — Schedule Lambda functions
- •Kubernetes CronJobs — Run containerized tasks
- •Vercel Cron — Trigger serverless functions
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