About Cron Generator
Edit a cron expression directly or field by field, and see both a plain-English reading and the next five times it will actually fire - the fastest way to confirm a schedule does what you meant.
The five fields
In order: minute, hour, day of month, month, day of week. A star means every value, */n means every nth, a-b is a range and a,b is a list. Day of week counts from 0 for Sunday.
The day-of-month and day-of-week trap
When both day fields are restricted, cron runs the job if either matches - not both. So 0 0 1 * 1 fires on the first of the month and on every Monday, which is rarely what anyone intends. This tool flags that combination when you write it.
Time zones
Next run times are shown in your local time zone, but most servers and container schedulers run cron in UTC. A job set for 9am local can fire at a very different hour in production, and will drift by an hour when daylight saving changes.
Frequently asked questions
- Why does my job run every minute?
- The minute field is probably a star. 0 9 * * * runs at 9am; * 9 * * * runs sixty times between 9 and 10.
- What does */15 mean?
- Every fifteenth value of that field, counting from zero - so minutes 0, 15, 30 and 45. It is not the same as every fifteen minutes from whenever the job was created.
- Are seconds supported?
- Not in standard Unix cron, which has a one-minute resolution. Some schedulers such as Quartz and Spring add a leading seconds field, making six in total.