Cron Expression Parser
Turn a cron schedule into plain English and see when it runs next.
How to use the Cron Expression Parser
- Paste a 5-field cron expression.
- Read the plain-English meaning.
- Check the next five run times.
About the Cron Expression Parser
Paste a standard five-field cron expression — minute, hour, day-of-month, month and day-of-week — and this parser checks each field in turn. It understands * (every value), */5-style steps, ranges such as 1-5 and comma lists such as 1,3,5. It then turns the schedule into a plain-English sentence and works out the next five times it will fire by stepping forward one minute at a time, up to a year ahead, and testing each minute against your rule.
That makes it handy for sanity-checking a crontab line before you commit it, or for decoding a schedule someone else wrote. A few honest details: it handles the classic five-field Unix/crontab format, not the six-field variant with a seconds column that some schedulers use; day-of-week accepts both 0 and 7 for Sunday; and the next-run times are computed in your device’s local timezone, whereas a real server usually runs cron in its own timezone — so mind the offset if your server sits elsewhere.
It all runs in your browser, so nothing you paste is uploaded. If you are juggling schedules and timestamps, the Unix timestamp converter pairs well with it, and the JSON formatter is handy for the config files these schedules often live in.
Frequently asked questions
Does it support cron expressions with seconds?
No. It parses the classic five-field format — minute, hour, day-of-month, month and day-of-week. The six-field variant that adds a leading seconds column, used by some schedulers and libraries, is not supported here; strip the seconds field first.
What is the difference between day-of-week 0 and 7?
Nothing — both mean Sunday. Cron traditionally allows 0 through 6 for Sunday to Saturday and also accepts 7 as an alternative name for Sunday, and this parser treats them the same.
What timezone are the next-run times shown in?
They are calculated in your device’s local timezone. A real server normally runs cron in its own configured timezone, which may differ, so if your server is elsewhere adjust for the offset when reading the predicted times.
What syntax can each field contain?
Each field accepts a star for every value, step values like every-fifth written with a slash, ranges written with a hyphen such as 1-5, and comma-separated lists such as 1,3,5. Anything outside a field’s valid range is flagged as invalid.
Is my cron expression sent anywhere?
No. Parsing, the plain-English explanation and the next-run calculation all happen in your browser, so the expression is never uploaded or stored.