Input
Result
The result will appear here.Your runs
Only runs that cost points are saved.
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Cron syntax is compact and easy to misread, and a schedule that fires at the wrong hour is usually discovered in production. Paste an expression and see its next five runs, plus what each field expanded to — which is where a misplaced asterisk becomes obvious.
How it works
- The five standard fields are parsed with step, range, list and name syntax.
- When both day-of-month and day-of-week are restricted, they are ORed, which is what cron does and what most people expect to be an AND.
- Next runs are computed in UTC; your scheduler's own timezone setting still applies.
Where your data goes
Nowhere. This tool runs entirely in your browser: the text you paste is processed by the page and is never transmitted to a server or written to a log.
When a run costs points, a one-line summary is saved to your own history so you can find it again. The summary records the shape of the run — sizes, counts, the values you looked up — never the content you pasted.
What it costs
Free up to 4.0 KB per run without an account. Past that, a run costs 1 points and is saved to your history.
Points come from signing up, checking in daily, commenting and completing your profile.
See how points workCommon questions
- Why does 0 0 13 * FRI run more often than I expected?
- That is the OR rule: with both day fields restricted, cron fires on the 13th of any month and on every Friday, not only on Friday the 13th. Restrict just one field to get an AND.
- What does */5 actually mean?
- Every fifth value starting from the bottom of the range — so in the minutes field, minutes 0, 5, 10 and so on, not five minutes after whenever the job last ran.
- Does this support seconds or @daily?
- No. It parses the five standard fields. Six-field expressions with seconds, and shorthands like @daily, are extensions specific to particular schedulers.
The open-source behind it
This tool is a self-contained implementation. harrisiirak/cron-parser (MIT) does the same job as a library — if you need this behaviour inside your own program, start there rather than calling a web page.
harrisiirak/cron-parserAlso known as
- cron parser
- crontab expression
- cron schedule checker
- cron next run
- cron generator