Cron Expression Parser
Explain a cron expression in plain language, validate every field and list the next 5 run times in your local time zone. Presets and @macros included.
Your inputs and files stay in your browser
Enter a cron expression to see the description
- Minute
- Hour
- Day
- Month
- Weekday
On this page
Type a five-field cron expression or an @macro and see in plain words when it runs, what each field means and the next five run times. The check is strict, so a typo such as minute 61 or a step of */0 is pointed out instead of being ignored.
Detailed Functionality
Supported syntax: *, single values, ranges 1-5, lists 1,15, steps */15 and 0-30/10, month names JAN–DEC, weekday names SUN–SAT, 7 as Sunday, L (last day of the month) and ? in the day fields, plus @yearly, @monthly, @weekly, @daily, @hourly and @reboot. Every field is checked against its range, and the error names the field and the allowed values.
The description is written in your interface language — for example 0 9 * * MON-FRI reads “At 09:00 Monday through Friday”. When both day of month and day of week are restricted, the tool follows the Vixie cron rule: the job runs when either of them matches. Next run times are calculated in your browser's time zone, up to 30 years ahead; a date that never occurs (0 0 30 2 *) is reported as having no upcoming runs.
Results update as you type, and quick preset buttons fill in common schedules. The next runs can be shown in several date formats — ISO 8601 with the time-zone offset, US style, your locale and others; the chosen format is remembered. Nothing is sent to a server.
Practical Examples
Nightly backup: 0 2 * * * — “Every day at 02:00”.
Polling: */15 * * * * — “Every 15 minutes”.
Month-end report: 0 0 L * * — “At 00:00 on the last day of the month”.
Day of month OR weekday: 0 0 13 * 5 — “At 00:00 on the 13th of the month or on Fridays”: it runs on every 13th and on every Friday, not only on Friday the 13th.
How to Use This Tool
Enter the expression
Type it into the Cron Expression field or click one of the Quick Presets.
Read the explanation
Human Readable shows the schedule in words, and Expression Parts lists what each of the five fields means.
Check the run times
Look at Next Execution Times and switch the Date format if needed.
Copy
Click Copy to copy the description, for example into a code comment.
Tips and Best Practices
- Cron has no time-zone field: the server runs jobs in its own zone (often UTC), while the times here are in your browser's zone.
- Only the classic five fields are supported; Quartz-style expressions with seconds or a year field are rejected.
- A step restarts in every larger unit:
0 */7 * * *runs at 00:00, 07:00, 14:00 and 21:00, then again at 00:00. @rebootruns once at system start, so it has no next run times.- To build an expression from separate fields, use the Cron Expression Generator.