What is a Cron Expression?
A cron expression is a string of five or six fields that defines a schedule for recurring tasks. Used in Unix cron jobs, Kubernetes CronJobs, GitHub Actions, and CI/CD pipelines, cron expressions specify when a command should run using minute, hour, day-of-month, month, and day-of-week fields. This parser shows the next run times and provides a visual builder.
Common use cases
- Building cron schedules for CI/CD pipelines
- Verifying when a Kubernetes CronJob will next execute
- Converting human-readable schedules to cron syntax
- Debugging why a scheduled task isn't running as expected
- Understanding complex cron expressions from legacy systems
How to use
- 1Paste or type a cron expression (5 fields, or 6/7 with seconds or a year), or build one in the Visual builder.
- 2Read the plain-English description and the field breakdown; pick your timezone to see the next 10 run times.
- 3Copy the description and run times, or pick a preset to start from a common schedule.
Frequently asked questions
What does */5 mean in a cron expression?
The */5 syntax means 'every 5 units.' In the minute field, */5 means every 5 minutes (0, 5, 10, 15...). In the hour field, */5 means every 5 hours (0, 5, 10, 15, 20).
What is the difference between 5-field and 6-field cron?
Standard Unix cron uses 5 fields (minute, hour, day, month, weekday). Some systems add a 6th field for seconds at the beginning. Quartz scheduler and Spring use 6-field cron expressions.