Cron Expression Generator
Build cron expressions with a visual editor and human-readable output.
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About the Cron Expression Generator
Cron's five fields — minute, hour, day of month, month, day of week — are compact and easy to get subtly wrong. This builds the expression from a schedule you describe, then translates the result back into a sentence so you can confirm it says what you meant before it goes anywhere near a server. It suits anyone setting up a backup, a nightly report, a cache warm or a cleanup job, particularly when the schedule is being written once and then trusted for months. The classic trap it helps you avoid is setting both day-of-month and day-of-week: standard cron runs the job when either field matches, not both, which quietly produces far more runs than intended. Two other things bite in practice — cron follows the clock of the machine running it, often UTC, and some schedulers expect a sixth seconds field.
How to use it
- Choose how often the job should run and at what time.
- Read the plain-English summary to confirm it matches your intent.
- Copy the expression into your crontab or scheduler.
Things worth knowing
- Setting both day-of-month and day-of-week is the classic cron trap: standard cron runs the job when *either* matches, not both.
- Cron follows the clock of whatever machine runs it, which is often UTC on a server even when you are not.
- Some schedulers add a seconds field at the front, making six fields rather than five — check your target's format before pasting.