Cron Expression Explainer
Read a cron schedule in plain English and see its next runs, so you find out now rather than at 3am.
What it does
Cron Expression Explainer reads the whole document before doing anything, so what comes back is either valid output or a specific error with the position that caused it — not a partially rewritten file.
When you need it
Usually when something has already gone wrong: a config file an application will not load, an API response that has to be read by a human, or an export that has to be checked before it goes anywhere near a database.
Limits and caveats
Key order is preserved as it appears in the input. Very large documents are limited by your device's memory rather than by an upload cap, since the parsing happens locally. Everything happens in your browser, so the file never leaves your device.
How to use the Cron Expression Explainer
- Paste the expression — @daily and friends work too.
- Read the sentence, and check the next runs against what you meant.
- Five fields: minute, hour, day-of-month, month, day-of-week.
Frequently asked questions
- Why does my schedule run more often than I expected?
- Probably the day-of-month / day-of-week trap: when both are restricted, cron fires when EITHER matches, not both. We warn you on screen when your expression hits it.
- Which timezone are the next runs in?
- Your computer's. Cron on a server runs in that server's timezone, which is very often UTC — so compare carefully before trusting the times.
- Do my files get uploaded?
- No. This tool runs entirely in your browser, so the file never leaves your device.