Build and understand a cron schedule — pickers and raw expression in sync, plain-English explainer, and the next runs, all local in your browser.
Cron expression
Edit the raw expression or the field pickers below — the other side updates to match.
Field editors
Pick a mode per field. Changes rebuild the expression above.
In plain English
Note: day-of-month and day-of-week are both set, so this runs when either matches (an OR), following standard cron behavior.
Next 5 runs
Upcoming fire times, computed offline from your device's clock.
No matching times in the next 5 years.
Cron Builder
Build, read, and preview a cron schedule without leaving the page. Everything runs locally in your browser — nothing you type is ever sent anywhere.
Two-way editing. Type a raw expression, or use the per-field pickers (Every / Every N / Range / Specific / Custom). Each side updates the other.
Pick a flavor. The Flavor menu sets the field layout, allowed special characters, and day-of-week numbering:
Standard / Unix (default) — 5 fields minute hour day-of-month month day-of-week. Day-of-week 0–7 (0 and 7 = Sunday). Macros like @daily work.
Unix with seconds — 6 fields, a leading seconds column.
Quartz (Java) — 6 or 7 fields sec min hour dom month dow [year]. Day-of-week 1–7 (1 = Sunday). Supports ?LW#; exactly one of dom/dow must be ?.
Spring @Scheduled — 6 fields sec min hour dom month dow. Day-of-week 0–7. Supports ?L# (no W).
AWS EventBridge — 6 fields min hour dom month dow year. Day-of-week 1–7; one of dom/dow must be ?. Supports LW#.
Syntax.* (every), a, a-b (range), */n (step), a-b/n, a/n, and lists like 0,15,30. Month names JAN–DEC and day names SUN–SAT work. Where the flavor allows: ? ("no specific value"), L (last), W (nearest weekday), and # (nth weekday, e.g. 6#3).
Day-of-month vs day-of-week. When both are set, cron fires when either matches (an OR) — the explainer flags this.
Plain English + next runs. A live description and the next 5 fire times (in your local time zone) update as you edit.
Presets & copy. Start from a common schedule, and copy the expression or the run list with the copy buttons.
Your expression and the chosen flavor are remembered on this device, so reopening the tool picks up where you left off. Times are shown in your local time zone; around daylight-saving changes the preview follows your system clock.