How it works
Five fields, read left to right
A cron expression is minute, hour, day of month, month and weekday, separated by spaces. Each field takes a star (every value), a number, a range such as 9-17, a step such as */15, or a comma list of those.
Months and weekdays also take their three-letter English names (JAN, MON). Weekday 0 and 7 are both Sunday. Type the whole expression in the box, or open a field row and pick a mode: every, one value, a range or a step.
minute hour day-of-month month weekday
Plain words and the canonical form
The sentence comes from cronstrue, an open-source library that turns cron into readable English or Vietnamese. The canonical form rewrites the expression with numbers instead of names and with lists deduplicated, which is how cron itself sees it.
The next runs
The tool walks forward day by day from the current minute and lists the first five times every field matches, in your browser’s time zone. Servers usually run cron in UTC or their own zone, so convert if yours differs.
When both the day-of-month and weekday fields are restricted, cron runs on days that match either of them, not both. The tool follows that rule and says so. A date that never occurs, such as 31 February, shows that the schedule never runs.
