Cron Expression Explainer
Explain any cron expression in plain English and preview its next runs, or build one from five fields — free, no upload, in your browser.
At 09:00, only on Monday through Friday.
- Thu 2026-09-17 09:00
- Fri 2026-09-18 09:00
- Mon 2026-09-21 09:00
- Tue 2026-09-22 09:00
- Wed 2026-09-23 09:00
Fields: minute hour day-of-month month day-of-week
| Operator | Means | Example |
|---|---|---|
* | any value | * * * * * — every minute |
, | a list of values | 0 9,17 * * * — at 09:00 and at 17:00 |
- | a range of values | 0 9 * * 1-5 — Monday through Friday |
/ | step values | */10 * * * * — every 10 minutes |
| Named schedule | Same as |
|---|---|
@yearly | 0 0 1 1 * |
@annually | 0 0 1 1 * |
@monthly | 0 0 1 * * |
@weekly | 0 0 * * 0 |
@daily | 0 0 * * * |
@midnight | 0 0 * * * |
@hourly | 0 * * * * |
@reboot | at startup — no clock schedule |
🔒 Parsed in your browser — nothing is uploaded.
Understand cron expressions at a glance
Type a standard 5-field cron expression (minute hour day-of-month month day-of-week) and see a
plain-English description plus the next five times it will run. A Local / UTC toggle switches the preview between
your local timezone and UTC — handy because most servers run cron in UTC. Presets cover the most common schedules
so you can start from a known-good pattern.
Supported syntax
Wildcards (*), steps (*/5), ranges (1-5), lists (1,15,30)
and month/day names (JAN, MON) are all understood. When both day-of-month and
day-of-week are set, it follows the standard cron rule of matching either.
Building one from the five fields
Switch to build and the expression is assembled from labelled minute, hour, day-of-month, month and day-of-week boxes, starting from a preset if you want one. The plain-English description and the next five run times appear underneath as you type, so you find out that a schedule never fires — or fires far more often than you meant — before it reaches your crontab rather than after. A step a field cannot honour, like */70 in a minute field that only counts to 59, is refused rather than quietly rounded down to hourly. The mode travels in the URL as ?mode=build.
Frequently asked questions
What timezone are the next runs shown in?
Either your device's local timezone or UTC — use the Local / UTC toggle above the list. Since most servers run cron in UTC, switching to UTC shows when the job actually fires. The preview uses your browser clock, so no server is involved.
Which cron format is this?
Standard 5-field cron (minute, hour, day-of-month, month, day-of-week), plus named macros — @yearly, @monthly, @weekly, @daily, @hourly and @reboot. Seconds (6-field) are not supported.
What happens with day-of-month and day-of-week together?
Like Vixie cron, when both are restricted a time matches if EITHER the day-of-month OR the day-of-week matches.
Can I build an expression instead of pasting one?
Yes. Switch to build and fill in the minute, hour, day-of-month, month and day-of-week boxes, starting from a preset if you like. The plain-English description and the next five run times appear underneath as you type, so a schedule that never fires is obvious before it reaches your crontab. The old crontab generator is now this mode.