Developer — tool

Cron Expression Parser

Explain five-field Unix cron and preview future runs.

About Cron Expression Parser

Validate traditional minute, hour, day-of-month, month, and day-of-week expressions and calculate upcoming executions.

The parser accepts traditional five-field Unix cron expressions and calculates upcoming run times using the browser environment. Each field is also labeled so the schedule is easier to review.

How to use it

  1. Enter or select your source data.
  2. Adjust the available options and run the tool.
  3. Review, copy, or download the result.

Common use cases

  • Preview a weekday job before adding it to crontab.
  • Check whether a maintenance expression runs as often as expected.
  • Translate a schedule into concrete upcoming dates for review.

Worked example

Parse 0 9 * * 1-5 to preview weekday runs at 09:00.

Limitations and responsible use

  • Only five-field Unix cron is supported; seconds, years, and vendor-specific macros are excluded.
  • Upcoming dates use the browser time zone, which may differ from the server running cron.
  • Cron day-of-month and day-of-week semantics can vary between schedulers.

Frequently asked questions

Does this tool schedule or execute a job?

No. It only validates an expression and previews dates.

Why might production run at a different local time?

The production scheduler may use UTC or another configured time zone.