Cron Next Run Time Calculator

How to use

1. 1Paste or type a standard five-field cron expression, for example 30 9 * * 1-5, or tap one of the examples.
2. 2Choose the time zone: Local uses your device, UTC matches most servers.
3. 3Pick how many upcoming runs to list, and optionally switch the start from Now to a custom date and time.
4. 4Read the next run times as ISO timestamps and readable dates, plus a plain-English summary and the average gap between runs.
5. 5Copy a single run, the full ISO list, or the complete summary to paste into a ticket, runbook, or chat.

About this tool

Cron Next Run Time Calculator answers the one question a crontab line never tells you on its own: when will it actually run next. You paste a standard five-field cron expression, the kind used by Vixie cron, most Linux distributions, Docker, and many CI systems, and the tool lists the next upcoming run times as real dates, not just a description of the rule. It works by parsing each field into the exact set of values it allows, then stepping forward minute by minute from a start instant and collecting the first matches, which is the same logic a cron daemon uses, so the times you see are the times the job would fire. Every part of standard cron syntax is supported: a star for every value, comma lists such as 0,15,30,45, ranges such as 1-5, and steps such as */15, 10-30/5, or 9/2. Month and weekday fields accept names as well as numbers, so JAN through DEC and SUN through SAT all work, and both 0 and 7 are treated as Sunday. The common macros @hourly, @daily, @midnight, @weekly, @monthly, @yearly, and @annually are expanded for you and shown in their normalized five-field form so you can see exactly what was simulated. The calculator also follows the often-misunderstood day rule correctly: when the day-of-month and day-of-week fields are both restricted, cron runs when either one matches, not only when both do, so a schedule like 0 0 13 * 5 fires on the 13th of the month and on every Friday. Time zones matter for scheduling, so you can read the results in your device local time or in UTC, which is what most servers run in, and switching between them shows how daylight saving can move a local clock time. You can start the preview from now or from any custom date and time, choose how many upcoming runs to list, and copy a single time, the whole list of ISO timestamps, or a full summary that includes the plain-English description and the average gap between runs. This tool is the missing companion to the catalog's cron explainer and cron generators: where those describe a schedule or help you build the expression, this one shows you the concrete clock times it produces, which is what you need when debugging a job that did not fire, confirming a new schedule before deploying it, or planning around a backup, report, or cleanup task. Everything is computed in your browser, so the expression you type is never uploaded.

Free to use. Works in your browser. No signup, no login.