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Free Cron Expression Builder

Build a valid cron expression from individual minute, hour, day, month, and weekday fields.

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Key Features

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Cron's five-field syntax is compact but unforgiving — getting the field order wrong silently schedules a job at the wrong time. This builder assembles a valid cron expression from five separate, clearly labeled fields, along with a plain-English description of the resulting schedule.

How it works

Enter the minute, hour, day-of-month, month, and day-of-week fields separately (using "*" for "every"). The builder joins them in the standard cron field order and generates a plain-English description of the schedule.

  1. Enter minute (0-59 or *).
  2. Enter hour (0-23 or *).
  3. Enter day of month (1-31 or *).
  4. Enter month (1-12 or *).
  5. Enter day of week (0-6 or *).
  6. Click Calculate to see your results.

Examples

Every weekday at 9:00 AM

Minute 0, hour 9, day-of-month *, month *, day-of-week 1-5 builds "0 9 * * 1-5" — running at 9:00 AM every Monday through Friday.

Who should use it

  • Building a cron schedule for a server task or scheduled job without memorizing field order.
  • Documenting a clear, readable description of what a scheduled job actually does.

Industry applications

  • DevOps and server administration
  • Software development and task scheduling

Advantages

  • Guarantees the fields are joined in the correct cron order every time.
  • Includes a plain-English description alongside the raw expression for a quick sanity check.

Limitations

  • Accepts standard numeric/range/wildcard syntax per field but does not validate every vendor-specific cron extension (like "@daily" shortcuts).

Common mistakes to avoid

  • Mixing up the day-of-month and day-of-week fields, which is a very common source of scheduling bugs.
  • Forgetting that day-of-week in cron is usually 0-6 (Sunday to Saturday), not 1-7.

Best practices

  • After building an expression, verify it with the Cron Expression Parser or your scheduler's own test/dry-run feature before deploying it to a real cron job.

Tips

  • When scheduling something for "every weekday," use day-of-week "1-5" and leave day-of-month as "*" — combining restrictive values in both date fields at once can produce confusing OR-based scheduling behavior in some cron implementations.

Frequently asked questions

Yes, with no signup and no limit on how many expressions you build.
Standard cron syntax always uses this order: minute, hour, day-of-month, month, day-of-week — this builder assembles the fields in that exact order regardless of how you fill them in.
It means "every" for that field — for example, "*" in the hour field means the job runs every hour.
This tool builds a new cron expression from individual schedule fields; the Cron Expression Parser goes the other way, explaining what an existing cron expression means.

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