Free Cron Explainer
Paste any cron expression and get a plain-English description of exactly when it runs. Supports standard 5-field cron plus handy @shortcuts.
Try: 0 9 * * 1-5 (weekday mornings) or @daily.
How to use the cron explainer
- Paste a cron expression into the box — five fields: minute, hour, day of month, month, day of week.
- Click Explain to see the schedule in plain English, plus a field-by-field breakdown.
- Shortcuts like
@daily,@hourly, and@weeklywork too.
Reading cron expressions
Cron’s five fields are minute (0–59), hour (0–23), day of month (1–31), month (1–12, or names like JAN), and day of week (0–7 where both 0 and 7 mean Sunday, or names like MON). An asterisk means "every", so * * * * * runs every minute. */5 means "every 5", ranges like 9-17 mean "9 through 17", and commas build lists like 1,15. The classic gotcha: when both day-of-month and day-of-week are restricted, cron runs when either matches, not both — a frequent source of surprise 3 AM jobs. Another common trap is forgetting that cron runs in the server’s timezone, not yours. When in doubt, paste the expression here before deploying it.
Frequently asked questions
What does */5 * * * * mean?
Every 5 minutes, around the clock. The */5 in the minute field steps through 0, 5, 10, 15 and so on, while the other four fields stay wildcards.
Do you support seconds or years?
The explainer covers standard 5-field cron plus @shortcuts, which is what most schedulers (including Linux crontab) use. Some systems add a seconds or year field — those variants are not covered.
Why did my job run twice in one day?
Almost always the day-of-month vs day-of-week trap: if both fields are restricted, cron fires when either matches. Keep one of them a wildcard unless you truly want both.
What timezone does cron use?
The timezone of the machine running the scheduler — usually the server, which may differ from your local time. Always confirm the server timezone for time-sensitive jobs.