About This Tool
Enter a cron expression and a reference time to get the upcoming run times in order, up to twenty of them. Alongside each run you get the weekday, the time remaining, how many times the job fires on an active day, and how many of the next thirty days are active. The calculation runs in either your local zone or UTC, and the UTC offset actually applied is printed with the result.
When both the day of month and the day of week are restricted, this follows the crontab union rule: the job runs when either field matches, not only when both do. Writing 13 for the day and Friday for the weekday means it runs on the 13th and on every Friday. When only one of the two is restricted, only that one applies. Calculates the standard five-field syntax as of October 2026.
Macros such as @reboot, extensions such as L, W, the hash sign and the question mark, name forms such as JAN or MON, and the six-field form with seconds are all rejected rather than guessed at, because implementations read them differently and a guess would produce wrong times. When calculating in a local zone, runs that land on a daylight saving transition are flagged, though whether they are skipped or repeated depends on the cron implementation. Field-by-field meanings are not covered here.
Frequently Asked Questions
No. When neither field is an asterisk, crontab runs on the union of the two. Setting day 1 and Monday means it fires on the 1st of every month and on every Monday, so treating it as an intersection badly undercounts the runs.
The hour skipped in spring does not exist at all, and the hour repeated in autumn occurs twice. This tool flags those runs in the note column; whether your cron actually skips or repeats them depends on the implementation you run.
It does not explain what each field means and it does not build an expression for you. It only calculates the upcoming run times for the expression you enter.