Cron Parser
Parse a cron expression (min hour day month weekday) and list the next run times.
About this tool
A cron expression is five numeric fields β minute, hour, day of month, month, day of week β describing when a recurring job runs. Its syntax is idiosyncratic and easy to misread, so this tool breaks the expression apart and lists the next run times so you can verify it does what you intend. Parsing runs in your browser and your input is never sent anywhere.
The five fields and the symbols they accept
- minute (0-59), hour (0-23), day of month (1-31), month (1-12), day of week (0-7, where 0 and 7 are Sunday).
- * means every value in that field (every minute, every hour, and so on).
- You can combine a range 1-5, a list 1,3,5, and a step */15 (every 15).
Common examples
- */15 * * * * β every 15 minutes.
- 0 9 * * 1-5 β 9:00 sharp on weekdays (Mon-Fri).
- 0 0 1 * * β midnight on the 1st of every month.
- 30 3 * * 0 β 3:30 every Sunday.
The biggest pitfall: day-of-month and day-of-week are OR
When you specify both day of month and day of week concretely, most cron implementations (Vixie cron) run if either matches β an OR. For example, 0 0 13 * 5 runs on "the 13th OR every Friday", not "the 13th AND Friday". It does not mean "only Friday the 13th each month", so be careful.
Watch for timezone drift
Server cron usually runs in that server's timezone (often UTC). Even if you write 0 9 * * * intending Japan time, a UTC server fires it at 18:00 Japan time. This tool computes the next runs in your device's local time, so if it differs from your production TZ, account for that gap when checking.
How to use
- Enter a cron expression (e.g. 0 9 * * 1-5).
- The expression is broken down into minute, hour, day, month, weekday.
- The next run times are listed from the current time.
FAQ
Is the cron expression I enter sent anywhere?
No. Parsing and calculating next run times run entirely in your browser, and the expression you enter is never sent to a server.
What timezone are the next run times shown in?
They are calculated and shown in your device local time (the browser timezone). Server cron runs in the server timezone, so account for the difference if your environment differs.
What happens if I specify both day of month and day of week?
Following common cron (Vixie cron) behavior, when both are specified concretely it runs if either the day of month or the day of week matches (an OR condition). If one is *, it follows the other condition.
How do the day-of-week numbers map?
0 is Sunday, 1 is Monday, and so on up to 6 for Saturday. 7 is also treated as Sunday, so you can specify Sunday with either 0 or 7.
Can I use a seconds field or @daily syntax?
This tool targets standard 5-field expressions (minute, hour, day of month, month, day of week). It does not support the 6-field form with a leading seconds field, nor shortcut syntax like @daily or @hourly.
Can I use steps (*/15) or ranges (1-5)?
Yes. In each field you can combine a wildcard (*), a range (1-5), a list (1,3,5), and a step (*/15 or 1-30/5). The interpreted result is broken down per field so you can verify it.