Cron Expression Parser

Validate and explain each field of a standard five-field cron expression.

This tool runs entirely in your browser. Your files are never uploaded to a server.

minute: every 15 minutes
hour: hours 9 through 17
day of month: every day of month
month: every month
day of week: day of weeks MON through FRI

Standard five-field cron syntax: minute, hour, day of month, month, day of week. The execution timezone is chosen by your scheduler.

What this tool does

Splits a Unix-style cron expression into minute, hour, day-of-month, month and weekday fields and explains the meaning of each part.

How to use it

Paste exactly five whitespace-separated fields. The result labels wildcards, fixed values, comma lists, ranges and slash steps for quick review.

Example

For */5 9 * * MON-FRI, the parser reports every five minutes, hour 9, every month day and month, and weekdays Monday through Friday.

Validation

Each token is checked against its field range. Named months and weekdays are accepted, while descending ranges, zero steps and extra fields fail.

How to interpret the result

The descriptions are field-by-field rather than a promise of exact run dates. Day-of-month and weekday interaction can vary by cron implementation.

Limitations

Only common five-field Unix syntax is covered. Nicknames such as @daily, Quartz extensions, timezone prefixes and next-run calculation are outside scope.

Privacy

All processing uses local browser APIs and this tool does not upload the values you enter.

Frequently Asked Questions

What does Cron Expression Parser do?
Splits a Unix-style cron expression into minute, hour, day-of-month, month and weekday fields and explains the meaning of each part.
How does it handle invalid input?
Each token is checked against its field range. Named months and weekdays are accepted, while descending ranges, zero steps and extra fields fail.
Is entered data uploaded?
All processing uses local browser APIs and this tool does not upload the values you enter.