⏱️ Cron Expression Tool
Build a cron expression with simple fields, or paste one to see what it means and when it runs next.
Frequently Asked Questions
What is a cron expression?
A cron expression is a 5-field string used to schedule recurring jobs: minute, hour, day of month, month, and day of week. Each field can be a number, *, a range (1-5), a list (1,3,5), or a step (*/15).
What does * mean in a cron field?
An asterisk (*) means "every" value for that field — e.g. * in the minute field means every minute, and * in the month field means every month.
How are the "next run times" calculated?
The tool simulates minute-by-minute from the current time (in your browser's local timezone) and finds the next 5 timestamps that match all five fields of the expression.
What happens if both day-of-month and day-of-week are restricted?
Following standard cron behaviour, if both fields are restricted (not *), the job runs when either condition matches (an OR, not an AND).
Is my cron expression sent anywhere?
No. All building, parsing and next-run calculations happen instantly in your browser using JavaScript.
How do ranges, lists and steps work in a cron field?
A range like 1-5 matches every value from 1 to 5 inclusive. A list like 1,3,5 matches exactly those values. A step like */15 matches every 15th value starting from the field's minimum (e.g. 0, 15, 30, 45 for minutes). These can be combined, e.g. 1-10/2.
What timezone are the next run times shown in?
All times are calculated and displayed in your browser's local timezone. If the cron job actually runs on a server in a different timezone, its real run times may differ from what's shown here.
Does this tool support 6-field cron expressions with seconds?
No. This tool supports the standard 5-field cron format (minute, hour, day of month, month, day of week) used by Unix cron and most schedulers. Some systems add a seconds field as a 6th value, which isn't supported here.