CRN
Cron Explainer
Turn a crontab expression into plain English.
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How to use Cron Explainer
Turn a crontab expression into plain English.
- Paste a five-field cron expression such as */15 * * * * into the Your text field.
- Press Run to read a plain-English description of when the job fires.
- Change a field and run again to compare two schedules.
When you actually reach for this
- You inherited a cron line from a teammate or a CI config and need to know exactly when it will fire before trusting it in production.
- A scheduled job ran at an unexpected time and you want to confirm whether the expression or the server timezone is the culprit.
Where this tool stops being accurate
- Cron has no year field, so it cannot express "only in 2027" — you must filter inside the script if you need that.
- The same expression means different wall-clock times on servers in different timezones; cron runs in the server local time unless you set TZ.
Frequently asked questions
What does Cron Explainer do?
Turn a crontab expression into plain English.
My job fired an hour off — is the expression wrong?
Probably the server timezone. Cron evaluates in local time, so check the host TZ (and Daylight Saving shifts) before rewriting the expression.
What does "0 0 1 * *" actually mean?
It means at 00:00 on the 1st day of every month — minute 0, hour 0, day-of-month 1, any month, any weekday. The five fields are minute, hour, day-of-month, month, day-of-week.