Boneyard Tools

Cron Expression Generator

Set each cron field to build a 5-field schedule, or start from a preset. The tool shows the expression and a plain-English summary of when it runs.

How to build a cron expression

  1. Pick a preset, or set the minute, hour, day-of-month, month, and day-of-week fields.
  2. Leave a field blank to keep its wildcard (*).
  3. Copy the generated cron expression for your crontab or scheduler.

Examples

Daily at 9:30 AM

minute 30, hour 9
30 9 * * *  (At 9:30 AM daily.)

Weekdays at 9 AM

hour 9, day-of-week 1-5
0 9 * * 1-5

Frequently asked questions

What are the five cron fields?

In order: minute, hour, day-of-month, month, and day-of-week. A * means every value for that field.

What does the plain-English summary cover?

It explains common schedules like every minute, hourly, daily at a time, weekdays, and specific days or months, and falls back to listing the fields for unusual patterns.

Are step and range values supported?

Yes. You can enter values like */15 for every 15 minutes or 1-5 for Monday to Friday, and they are kept as-is in the expression.

Is day-of-week 0 Sunday or Saturday?

Sunday is 0 and Saturday is 6, matching the standard Unix cron convention.

Is my data private?

Yes. The expression is built entirely in your browser and nothing is uploaded.

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