IT Consulting
Illustration of a cron expression 0 9 * * 1-5 next to a clock, with a plain-English explanation reading runs weekdays at 9 AM

Cron Expression Builder

Type or paste a 5-field cron expression below, or use a preset — the explanation updates live. Runs entirely in your browser.

Build from individual fields instead
ℹ️ Cron syntax reference
  • Five fields, in order: minute (0-59), hour (0-23), day of month (1-31), month (1-12 or JAN-DEC), day of week (0-7 or SUN-SAT, both 0 and 7 mean Sunday).
  • * means "every value"; */N means "every N units"; A-B is a range; A-B/N is a stepped range; A,B,C is a list — these can combine, e.g. 1-5,10-15/2.
  • Runs entirely client-side — nothing you type here is ever sent anywhere. The JSON API below is a separate, opt-in endpoint for scripts.
💻 Show API usage example (cURL) 
curl -sS "https://devops.majbase.com/cron-builder/api" \
    --data-urlencode 'cron=0 9 * * 1-5' \
    --data-urlencode 'count=5'

Returns JSON: {"summary": "..."|null, "breakdown": {"minute": "...", "hour": "...", "dayOfMonth": "...", "month": "...", "dayOfWeek": "..."}, "next_runs": ["2026-08-17T09:00:00", ...]}, or {"error": "..."} for a malformed expression. count is optional (default 5, max 20); next_runs times are in the server's local time zone, starting from now.