Cron Expression

A Cron expression is a syntax used to specify a repeating sequence of time. A Cron expression comprises of six mandatory fields and one optional field. All expressions are separated by a space. The fields are described in the following table:

Field name	Allowed values	Allowed special characters
Seconds	0-59	, - * /
Minutes	0-59	, - * /
Hours	0-23	, - * /
Day-of-month	1-31	, - * ? / L W
Month	1-12 or JAN-DEC	, - * /
Day-of-Week	1-7 or SUN-SAT	, - * ? / L #
Year (optional)	empty, 1970-2199	, - * /

The asterisk (*) character specifies all values. For example, * in the minute field implies every minute.

The question mark (?) character specifies the day-of-month field and day-of-week field. You can select only one field at a time.

The hyphen (-) character specifies the range. For example, 10-12 in the hour field implies the hours 10, 11 and 12.

Example - 10 * 13 1,14 * ? *

Seconds = 10 (10 second)

Minutes = * (all)

Hours = 13 (1 pm)

Day of Month = 1,14 (First and fourteenth one-based)

Month = * (all)

Day of Week = ? (don't care)

Year (optional) = * (all)

Learn more: Quartz scheduler cron format

Class CronExpression