Which cron flavour is it?

Standard five fields: minute, hour, day of month, month, day of week. That covers Linux crontab, GitHub Actions and most schedulers.

Why did my job run at the wrong time?

Almost always a timezone mismatch between the scheduler and your expectation. The answer tells you what to check.

Cron Expression Generator

Write the schedule in plain words — every weekday at 9:15, every 15 minutes between 9 and 6, the first Monday of the month — and get the cron expression back.

Every field is validated before you paste it into crontab, GitHub Actions or a Kubernetes CronJob, and out-of-range values are caught. The answer explains each field and warns about timezone differences.

Describe when a job should run and get the five-field cron expression, with every field explained and validated.

Open the tool — this example is already filled in

Frequently asked questions

Which cron flavour is it?: Standard five fields: minute, hour, day of month, month, day of week. That covers Linux crontab, GitHub Actions and most schedulers.
Why did my job run at the wrong time?: Almost always a timezone mismatch between the scheduler and your expectation. The answer tells you what to check.

Related tools

Python Error Explainer

Paste a Python traceback and get the cause in plain words, the fix, and how to confirm it worked.