Cron Expression Interpreter

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Make sense of any cron schedule without guessing. Paste a 5-field crontab expression (minute hour day month weekday) or a 6-field one with a leading seconds column, and instantly get a clear, plain-language explanation of when it fires — plus a list of the next times it will actually run, computed in your own local time zone. The interpreter understands ranges (1-5), lists (1,3,5), steps (*/15, 10-50/5), month and weekday names (JAN-DEC, MON-FRI), the Sunday-as-0-or-7 convention, and common shortcuts like @daily and @weekly. It even applies cron's quirky day-of-month / day-of-week OR rule so the upcoming-run preview matches what real cron daemons do. Everything is parsed and calculated locally in your browser — nothing is uploaded — so it is safe, fast, and works offline. Ideal for sanity-checking a crontab line, a CI schedule, or a Quartz trigger before you ship it.

Try:

How to use

Type or paste a cron expression into the box, or click one of the sample expressions to load it. The plain-language meaning appears immediately, followed by the next scheduled run times rendered in your local time zone. Use the dropdown to show more upcoming runs, copy any run time with one click, and press Clear to start over. Both the classic 5-field format and the 6-field format with leading seconds are supported.

Frequently asked questions

Which cron syntax is supported?
Standard crontab syntax: five fields (minute, hour, day-of-month, month, day-of-week) or six fields when the first is a seconds column. Each field accepts * (any), ranges like 1-5, lists like 1,3,5, and steps like */15, 5/10, or 10-50/5. Month names (JAN-DEC) and weekday names (SUN-SAT) are recognised case-insensitively, weekday 7 is treated as Sunday, and the macros @yearly, @annually, @monthly, @weekly, @daily, @midnight, and @hourly are expanded.
What time zone are the next-run times in?
All upcoming run times are computed and displayed in your device's local time zone, which is shown above the list. Cron itself has no built-in time zone — a daemon runs in whatever zone its host or configuration uses — so treat this preview as 'what would happen if this schedule ran on a machine set to my local time.' The tool does not convert between zones.
How are day-of-month and day-of-week combined, and is anything sent to a server?
Cron uses an OR rule: when both the day-of-month and day-of-week fields are restricted (neither is *), the schedule fires on a day that matches EITHER field — so '0 0 13 * FRI' runs at midnight on the 13th and on every Friday. When one field is *, only the other constrains the day. And nothing is sent anywhere: parsing, the description, and the next-run calculation all happen locally in your browser, with no uploads, logging, or account, and it keeps working offline.