Cron expression explainer
This tool explains what a cron schedule means and when it runs next. System admins and developers use it to check crontab lines, CI schedules and cloud scheduler settings before they deploy them.
- Runs in your browser
- Free, no account needed
- Copy or download the result
Result
Example
*/15 9-17 * * 1-5
Cron: */15 9-17 * * 1-5 Meaning: At every 15th minute past hours 9 through 17 on Monday through Friday. Next 5 runs after 2026-11-01 00:00 UTC: 2026-11-02 09:00 UTC (Monday) 2026-11-02 09:15 UTC (Monday) 2026-11-02 09:30 UTC (Monday) 2026-11-02 09:45 UTC (Monday) 2026-11-02 10:00 UTC (Monday) Field Value Matches Minute */15 0, 15, 30, 45 Hour 9-17 9-17 Day of month * 1-31 Month * 1-12 Day of week 1-5 1-5
How to use the cron expression explainer
- Enter a Cron expression, such as */15 9-17 * * 1-5 or @daily.
- Set the Start date and time (UTC) as YYYY-MM-DD HH:MM.
- Press Run to see the meaning and the next 5 runs.
- Use Copy result or Download to keep the explanation.
How it works
The five fields are minute (0 to 59), hour (0 to 23), day of month (1 to 31), month (1 to 12 or JAN to DEC) and day of week (0 to 7 or SUN to SAT, where 0 and 7 both mean Sunday).
Each field accepts *, single values, lists with commas, ranges with a dash and steps with a slash, such as */15 or 1-30/5. The macros @yearly, @annually, @monthly, @weekly, @daily, @midnight and @hourly also work.
When both day fields are restricted, the job runs when either one matches. If one of them starts with *, both must match, as in Vixie cron.
Next runs are listed strictly after the start time, in UTC. If no date matches within 400 years, as with February 30, the tool says the schedule never runs.
Seconds or year fields and the Quartz characters ?, L, W and # are rejected, and out-of-range values or backward ranges are reported.
Everything runs in your browser. Your input is not uploaded or stored.
Questions and answers
What does */15 mean in cron?
It means every 15th value of that field, starting from the lowest. In the minute field it runs at minutes 0, 15, 30 and 45.
Are the times in my time zone?
No. Run times are shown in UTC. Cron itself uses the time zone of the server or scheduler, so convert the times if yours is different.
What is the difference between 0 and 7 for day of week?
Both mean Sunday. Many cron versions accept either one.
Why does my 6-field expression fail?
It probably has a seconds field, as used by Quartz and some other schedulers. Standard cron has exactly 5 fields.