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ToolWrenPaste a 5-field cron expression to see what it means in plain English and exactly when it will next run. Perfect for sanity-checking schedules before you deploy them.
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Cron is a free, private online tool that lets you translate a cron expression into plain English and preview the next scheduled run times. It runs entirely in your browser, so nothing you enter is uploaded to a server.
Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.
A standard cron line has five fields: minute hour day-of-month month day-of-week. For example */15 9-17 * * 1-5 means every 15 minutes, 9am–5pm, Monday to Friday.
* means "every", */n means "every n", a-b is a range and a,b,c is a list. Day-of-week accepts 0–7 (0 and 7 are both Sunday) and month/day names like jan or mon.
The tool simulates the schedule forward from now to show the next five fire times in your local time zone — the fastest way to confirm a cron does what you intend.
Cron is the time-based job scheduler used on Unix-like systems, and a cron expression is the compact string that tells it when to run something. The standard form has five space-separated fields — minute, hour, day-of-month, month and day-of-week — so */15 9-17 * * 1-5 means 'every 15 minutes, 9am to 5pm, Monday to Friday'. This tool turns that terse syntax into plain English and shows the next run times.
Each field accepts a few operators. An asterisk * means 'every' value. A list like 1,15,30 picks specific values. A range like 9-17 covers a span. A step like */15 means 'every 15'. Day-of-week accepts 0–7 (where both 0 and 7 are Sunday) and the month and weekday fields also accept names like jan or mon. Combining these covers almost any schedule.
Cron's density makes it easy to misread — is 0 0 1 * * monthly or daily? Getting it wrong can mean a backup that never runs or an email blast at the wrong hour. The explainer translates the expression into a sentence so you can confirm intent at a glance before deploying, which catches mistakes that a quick eyeball of the raw string would miss.
Beyond describing the schedule, the tool simulates the cron clock forward from the current moment and lists the next several fire times in your local time zone. Seeing concrete upcoming dates is the fastest way to verify a complex expression actually behaves as you expect — far more reliable than reasoning about the fields in your head.
One subtlety trips up even experienced engineers: when both the day-of-month and day-of-week fields are restricted, standard cron runs the job when either matches, not both. If only one is restricted, only that one applies. This tool follows the POSIX behaviour, so its predictions match what real cron daemons do.
This explainer uses the classic five-field format. Some systems add an optional seconds field at the front or a year field at the end (Quartz, certain libraries) — if you use those variants, drop the extra field before pasting. Everything runs locally in your browser.