Cron Expression Explainer
Type a cron expression to read it as a sentence, check that it is valid, and see when it will run next in your time zone.
Dieser Inhalt ist auf Englisch.
Five fields: minute (0 to 59), hour (0 to 23), day of the month (1 to 31), month (1 to 12, or JAN to DEC) and day of the week (0 to 6, or SUN to SAT).
Next five run times
Durchgerechnete Beispiele
Running every fifteen minutes
*/15 * * * *
Runs at minutes 0, 15, 30 and 45 of every hour, every day.
The slash makes a step, so */15 in the minute field means every 15 minutes.
Weekday morning job
0 9 * * 1-5
Runs at 09:00 on Monday to Friday, every week.
The dash makes a range of days, so 1-5 covers Monday through Friday in the day of week field.
Über Cron Expression Explainer
Cron is the scheduling system used on many servers to run jobs at fixed times, such as a backup every night or a report on the first day of each month. Its schedule is written as a short line of five fields: minute, hour, day of the month, month and day of the week. Those fields use stars, numbers, dashes, commas and slashes, which can be hard to read at a glance. This explainer translates any valid expression into a plain sentence, so you can confirm that a job will run when you expect it to.
The tool also works out the next five times the schedule will run, starting from the current moment in the time zone of your device. Each run is shown with its day, date and time, so you can check a schedule against a calendar. It understands month and day names such as JAN and MON, accepts Sunday as either 0 or 7, and recognises the shortcuts @daily, @weekly and @monthly. Invalid entries are explained in words, so you know exactly which field to correct.
So verwenden Sie Cron Expression Explainer
- Type a five-field cron expression into the box, or choose one of the example buttons.
- Read the plain English sentence that describes when the job runs.
- Check the next five run times, which are listed in your time zone.
- Correct any message shown in red, then confirm the new sentence matches what you intended.
Typische Einsatzzwecke
- Checking that a nightly backup really runs at 2am and not 2pm
- Confirming the weekday pattern of a report before it is put into production
- Explaining a server schedule to a colleague who does not read cron
- Testing a schedule that should only run on the last few days of a month
Häufige Fragen
What order do the five fields come in?
The fields are minute, hour, day of the month, month and day of the week, in that order. The minute field runs from 0 to 59, the hour from 0 to 23, the day of the month from 1 to 31, the month from 1 to 12 and the day of the week from 0 to 6, where 0 is Sunday. A single star in a field means every possible value for that field.
What does */15 mean in a cron expression?
The slash means a step. The expression */15 in the minute field means every 15 minutes, starting from the first possible value, so the job runs at minutes 0, 15, 30 and 45 of every hour. A step can also start from a set value, such as 5/15, which runs at minutes 5, 20, 35 and 50.
Why does a schedule run on a day I did not expect?
When both the day of the month and the day of the week are given, most cron systems run the job if either one matches. So 0 0 1 * 1 runs on the first of each month and also on every Monday. To run only when both conditions are true, a script must check the second condition itself. The sentence produced by this tool says or between the two conditions to make this clear.
Are the run times shown for my time zone or the server?
The run times are calculated in the time zone of the device you are using now. A server may be set to a different time zone, which can shift the times when a job actually runs. Check the server time setting before you rely on the exact hour, especially around daylight saving changes.
Does this support seconds or year fields?
Only the five standard fields are supported. Some job schedulers add a seconds field at the start or a year field at the end, which this tool does not read. If an expression has more or fewer than five fields, the message tells you how many it found, so you can adjust it.