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Cron Builder & Explainer

Paste a cron expression, get the plain-English sentence and the next fire times — dialect and timezone explicit.
5-field6-field (seconds)5 runs1025Insert sampleClearCron expressionTimezone

Fire times are computed live in your browser against the current moment — they appear here once the page loads, never baked in.

- The dialect is explicit: five fields (minute hour dom month dow) or six with a seconds field first. A 6-field expression under the 5-field dialect is an error naming both counts — never a guess.
- The timezone is part of the question, not a display detail: the same expression fires at different instants in different zones, so fire times are computed in the zone you name (cron-parser’s tz) and shown in it (Intl).
- Day-of-month × day-of-week is the Vixie OR rule: when BOTH are restricted (neither is *), a date matching EITHER fires. Every other field combination is an AND — the badge above says when the OR rule applied.
- The sentence is cronstrue’s, labeled as its own output; the fire times are cron-parser’s. Two engines, two jobs, neither blended.
Working

Processing on this device.

waiting for the current moment to be captured in the browser

Next door in Developer

- Timezone converter (/time/timezone-converter)
- Regex tester (/dev/regex-tester)
All developer tools (/dev)

Canonical HTML: https://nutter.tools/dev/cron
Markdown version: https://nutter.tools/dev/cron/index.md
Plain-text version: https://nutter.tools/dev/cron/index.txt
Agent index: https://nutter.tools/llms.txt