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Cron Expression Explainer

Paste a crontab line to read it in plain English and see when it next runs.

About this tool

Cron schedules are terse and easy to misread. This decoder turns the five fields, minute hour day-of-month month day-of-week, into a plain sentence, breaks down each field, and lists the next run times so you can confirm a schedule before you trust it. It supports asterisks, steps, ranges and lists.

How to read a cron schedule

Cron is the standard way to schedule recurring tasks on Unix-like systems, and a cron expression is five fields separated by spaces: minute, hour, day-of-month, month, and day-of-week. Each field holds a number, a list, a range, or an asterisk meaning "every". So 0 9 * * 1 means minute 0, hour 9, every day-of-month, every month, on Monday, in other words 9:00 every Monday.

The building blocks. An asterisk * means every value; */5 in the minute field means every five minutes; a comma lists values (1,15); a hyphen gives a range (9-17 for business hours). Days of the week run 0–6 from Sunday, and many systems accept names like MON. The tool above turns any expression into plain English so you can confirm it does what you meant.

The traps. The two day fields (day-of-month and day-of-week) are OR-combined when both are set, which surprises people. Cron also uses the server's timezone, so a job may run at an unexpected local time, and it does not catch up on runs missed while the machine was off. Always sanity-check a new schedule against a human-readable translation before relying on it.