Format
A cron expression is a string comprised of 6 or 7 fields separated by white space. Fields can contain any of the allowed values, along with various combinations of the allowed special characters for that field. The fields are as follows:
Field Name |
Mandatory? |
Allowed Values |
Allowed Special Characters |
|---|
Seconds |
YES |
0-59 |
, - * / |
Minutes |
YES |
0-59 |
, - * / |
Hours |
YES |
0-23 |
, - * / |
Day of month |
YES |
1-31 |
, - * ? / L W C |
Month |
YES |
1-12 or JAN-DEC |
, - * / |
Day of week |
YES |
1-7 or SUN-SAT |
, - * ? / L C # |
Year |
NO |
empty, 1970-2099 |
, - * / |
So cron expressions can be as simple as this: * * * * ? *
or more complex, like this: 0 0/5 14,18,3-39,52 ? JAN,MAR,SEP MON-FRI 2002-2010