Calendar, time-zone, and inclusion rules are calculated separately.
27
Data & developer
Cron Expression Explainer
Validates minute, hour, day-of-month, month, and day-of-week fields and turns common expressions into a short schedule. It also reminds you to verify the server time zone.
✓ Free✓ No account✓ In-browser
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What does this tool do?
Validate classic five-field cron expressions and explain them in plain language.
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Your result will appear here.
APPLICATION AND DECISION GUIDE
Cron Expression Explainer: method and usage
Validates minute, hour, day-of-month, month, and day-of-week fields and turns common expressions into a short schedule. It also reminds you to verify the server time zone.
a date, time, duration, or schedule with an explicit format and time zone Confirm the shape first with a small example containing no personal data.
a normalized temporal value, calculation summary, and ambiguous-zone warnings
Practical steps
- Paste a five-field cron expression.
- Review the validation and explanation for every field.
- Verify the server time zone separately before production use.
UTC equivalence, daylight-saving transitions, boundary dates, and applicable official calendar rules
Cron semantics vary by scheduler; confirm the target scheduler's field count, time zone, and daylight-saving behavior before production use.
Suitable use cases
- CI/CD schedules
- Checking backup jobs
- Documenting server tasks
Worked decision record
Review a five-field cron expression, server time zone, and daylight-saving impact together so a nightly backup does not run at an unexpected hour.
Try `0 3 * * 1-5`; separately record that the target scheduler uses the classic five fields and which time zone interprets the value `3`.
Minute, hour, and weekday fields validate separately; the explanation says 03:00 on weekdays and the scheduler's next three production run times agree.
If the target uses six or seven fields, different weekday numbering, or UTC, do not copy the explanation into production; verify it with that scheduler's own preview.
LEARN THE WORKFLOW
Guides for this tool
Reliable Scheduling with Cron and Unix Time
Prevent time zones, DST, field order, and second-vs-millisecond mistakes from breaking scheduled jobs.
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Read guide →QUICK REFERENCE
Open cheat sheet →Cron Cheat Sheet: Five-Field Scheduling Guide
An example-driven reference to classic cron fields, wildcards, ranges, lists, steps, and production safety.
ABOUT THIS TOOL
Frequently asked questions
What input does Cron Expression Explainer accept?+
a date, time, duration, or schedule with an explicit format and time zone Try `0 3 * * 1-5`; separately record that the target scheduler uses the classic five fields and which time zone interprets the value `3`.
What does Cron Expression Explainer return?+
a normalized temporal value, calculation summary, and ambiguous-zone warnings Minute, hour, and weekday fields validate separately; the explanation says 03:00 on weekdays and the scheduler's next three production run times agree.
How should I validate Cron Expression Explainer output?+
UTC equivalence, daylight-saving transitions, boundary dates, and applicable official calendar rules If the target uses six or seven fields, different weekday numbering, or UTC, do not copy the explanation into production; verify it with that scheduler's own preview.
Does Cron Expression Explainer send or store input on a server?+
Tool input is processed in the active tab. Saving to the Workstation or transferring to another tool is a separate choice. Consider browser extensions and shared devices separately; the privacy page explains advertising and network connections.