Understanding Cron Expressions (5 Fields Explained)
A cron expression is five fields that define a schedule: minute, hour, day of month, month and day of week. Learn the syntax with clear, worked examples.
A cron expression is five fields separated by spaces that define when a task runs: minute, hour, day-of-month, month and day-of-week. For example, 0 9 * * 1 means "at 09:00 every Monday".
The five fields
In order, with their ranges:
- Minute — 0 to 59
- Hour — 0 to 23
- Day of month — 1 to 31
- Month — 1 to 12
- Day of week — 0 to 6 (0 = Sunday)
The special characters
*— every value ("any")*/5— every 5 units (a step)1,15— a list of specific values9-17— a range of values
Worked examples
*/15 * * * *— every 15 minutes0 9 * * 1— 09:00 every Monday0 0 1 * *— midnight on the 1st of every month0 8-18 * * 1-5— every hour from 08:00 to 18:00 on weekdays0 0 * * 0— midnight every Sunday
Build one visually
Instead of memorising the syntax, use the cron expression generator to build and read a schedule field by field. Working with times and epochs too? See the timestamp converter. Related: What is JSON and how to format it.