Cron Expression Builder
Build a cron schedule expression field-by-field and get a plain-English description plus the next 5 run times. Use the dropdowns for common patterns, or paste a custom expression to override them. Everything is computed locally with JavaScript's Date object.
How to use
- 1
Set each field
Use the five dropdowns (minute, hour, day-of-month, month, day-of-week) to pick a common pattern. The generated expression updates instantly.
- 2
Optionally enter a custom expression
If the dropdowns do not cover your case, type a custom expression in the text field. It takes priority over the dropdowns when present.
- 3
Read the plain-English description
Below the expression you will see a friendly summary like “at minute 0, every hour from 9 to 17, on Monday-Friday”.
- 4
Preview the next 5 runs
Click Show next 5 runs to compute the upcoming fire times in your local timezone. The scan covers up to one year.
Common use cases
- Schedule a cron job on a Linux server or Kubernetes CronJob.
- Document a recurring job in a README or runbook.
- Verify a cron expression produces the times you expect before deploying.
- Translate an English schedule like “every weekday at 9am” into a cron expression.
Limitations
- Five-field standard cron only — seconds, years, and special macros like
@dailyare not supported. - Special characters
L,Wand#are not supported. - Next-run scanning checks one minute at a time and caps at one year, so impossible combinations (e.g. Feb 30) return no runs.
- Times are shown in your browser's local timezone, not UTC.
Frequently asked questions
Related tools
View allUnix Timestamp Converter
Convert between Unix timestamps and human-readable dates.
Regex Tester
Test JavaScript regular expressions against sample text.
UUID Generator
Generate RFC 4122 UUIDs (v4) in bulk.
JSON Formatter
Beautify and indent JSON with 2 or 4 spaces.