Cron Expression Explainer
Paste a cron expression and read it back in plain English.
How to use
- Paste a 5-field cron expression.
- Each field is explained in plain English.
- Adjust the values to see the schedule change.
How the Cron Expression Explainer works
Translates a cron expression into plain English, so you can confirm a schedule means what you think before it runs in production.
A standard cron line has five fields — minute, hour, day of month, month, day of week — each accepting a value, a list, a range, or a step. The tool reads each field and describes the resulting schedule.
┌minute ┌hour ┌day-of-month ┌month ┌day-of-week
* * * * *
Worked example
0 9 * * 1-5 means 9:00 AM every weekday. */15 * * * * means every fifteen minutes.
Things worth knowing
- When both day-of-month and day-of-week are restricted, most cron implementations run on either match, not both. This surprises people regularly.
- Cron runs in the server's timezone, so daylight saving transitions can skip or repeat a job.
- Some systems (Quartz, AWS) add a seconds or year field, making six or seven fields rather than five.
Frequently asked questions
What are the five fields?
Minute, hour, day of month, month and day of week — in that order.
What does */15 mean?
A step value — '*/15' in the minute field means every 15 minutes.
How do I run a job on the last day of the month?
Standard cron cannot express it. Use L in Quartz-style cron, or schedule daily and exit early unless tomorrow is the first.