Cron Calculator

Build a cron expression field by field and preview the next run times.

A cron expression has five fields: minute, hour, day of month, month, weekday. For each field choose a mode — any, single, range, list or every-N — and the calculator builds the expression and shows the next runs, evaluated with the same library Upcron uses for heartbeats.

Understanding the modes

• Any (*) — every unit in the field
• Single — one fixed value (e.g. 30 minutes)
• Range — from a to b (e.g. 10-20)
• List — several values (e.g. 5,15,25)
• Every N (*/n) — every n units (e.g. */15 every 15 minutes)

Example: Minute: Single 0 · Hour: Single 9 · Day: Any · Month: Any · Weekday: Range 1-5 → 0 9 * * 1-5, which runs at 09:00 every weekday.

Using it with a heartbeat

Once an expression looks right, create a heartbeat in the app, paste the expression into the cron schedule field and set the matching timezone. The grace period is then measured from the expected run times.