Cron Expression Parser

Read a cron expression in plain English.

Cron Expression Parser translates a cron schedule into a sentence — "at 02:30 on the first day of every month" — and lists the next ten times it will fire. It supports five and six-field forms, step and range syntax, named months and weekdays, and the common @-shortcuts. Parsing runs in your browser and works offline.

This tool needs JavaScript, because the work happens on your device rather than on a server. Everything below — how it works, the FAQ and the related tools — is readable without it.

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How to use Cron Expression Parser

Paste a cron expression, or build one with the fields.
Read the plain-English description.
Check the next ten scheduled times.

Questions about Cron Expression Parser

Five fields or six?

Classic Unix cron has five: minute, hour, day of month, month, day of week. Quartz and Spring add a leading seconds field, making six. The parser detects which you pasted and says so, because misreading it shifts everything by one position.

What happens when day-of-month and day-of-week are both set?

Standard cron treats them as OR, not AND — 0 0 1 * MON runs on the 1st and every Monday, which surprises almost everyone. The description states this explicitly when it applies.

Which time zone do the next runs use?

Your local zone, with UTC shown alongside. Real cron uses the server's zone, so check what that is before trusting a schedule across a DST boundary.

Does it run my schedule, or only describe it?

Only describe it. Nothing is scheduled, stored or executed here — the next-run list is arithmetic on the expression, which is what makes it safe to check a schedule before it goes anywhere near a server.

Are @daily and @reboot supported?

The shortcuts that map to a fixed schedule — @yearly, @annually, @monthly, @weekly, @daily, @midnight and @hourly — are expanded to their five-field form and described normally. @reboot is not a schedule at all, since it depends on when the machine boots, so there is nothing to compute and it is not accepted here.

Is Cron Expression Parser really free, with no limits?

Yes. There is no account, no daily cap, no file-size tier and no watermark, because there is no server cost to recover. The site is funded by clearly disclosed partner recommendations on the Partners page, never by metering the tools.

Are my files or text uploaded when I use Cron Expression Parser?

No. Everything is processed by JavaScript running in your browser, on your device. You can verify it: open your browser's developer tools, switch to the Network tab, and use the tool. You will see no request carrying your data — because there is nowhere for it to go.