How do cron expressions work?
A 5-field cron defines scheduled tasks using minute, hour, day of month, month, and day of week.
This tool converts ranges, lists, steps, and stars into readable text.
Cron Expression Translator
Turn 5-field cron expressions into readable schedule explanations.
Cron Expression Translator
Turn standard 5-field cron expressions into readable schedule explanations.
Enter minute, hour, day of month, month, and day of week in order.
Examples: `*/15 9-17 * * 1-5`, `0 0 1 * *`, `30 6 * 1,7 1`
Summary
Valid cronRuns at 0, 15, 30, 45 minute(s), 9, 10, 11, 12, 13, 14, 15, 16, 17 hour(s), on every value day(s) of every value, and Mon, Tue, Wed, Thu, Fri.
Minute
0, 15, 30, 45
Hour
9, 10, 11, 12, 13, 14, 15, 16, 17
Day of month
every value
Month
every value
Day of week
Mon, Tue, Wed, Thu, Fri
Parsed fields
Minute
*/15
Normalized
*/15
Values
0, 15, 30, 45
Hour
9-17
Normalized
9-17
Values
9, 10, 11, 12, 13, 14, 15, 16, 17
Day of month
*
Normalized
*
Values
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31
Month
*
Normalized
*
Values
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
Day of week
1-5
Normalized
1-5
Values
1, 2, 3, 4, 5
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Which cron syntax is supported?
Only the standard 5-field cron format is supported.
Quartz and other 6/7-field variants are out of scope for this release.
Limits of the 5-field cron model
This page focuses on the standard minute, hour, day of month, month, and day of week fields.
Seconds, year fields, aliases, and Quartz-like extensions vary by scheduler and should be verified separately.
Ranges, lists, and step values
Comma lists describe multiple values, hyphen ranges describe start-to-end spans, and slash steps describe recurring intervals.
When these forms are combined, a readable explanation helps, but the production scheduler must still support the same syntax.
Time zone and daylight-saving impact
A cron expression does not define a time zone by itself; actual execution usually depends on the server, container, or scheduler setting.
During daylight-saving transitions, some local times can be skipped or repeated, so critical jobs should be checked in staging and logs.
Checks before release
Compare the explanation with the intended run window and manually test a few sample dates.
For high-impact tasks such as billing, notifications, or deletion jobs, a cron string alone should not be treated as sufficient assurance.