Quartz Scheduler

* Scheduling Guide

Quartz Scheduler extends standard cron with a mandatory seconds field (making it 6 or 7 fields total with an optional year), plus four special characters that solve real scheduling problems. L in the day-of-month field means "last day of the month," solving the variable-month-length problem cleanly. W finds the nearest weekday to a given date, useful for "run on the nearest business day to the 15th." # selects a specific occurrence of a weekday in a month — 2#1 means "the first Monday" and 6#3 means "the third Friday." ? is used in either day-of-month or day-of-week (but not both) to indicate "no specific value," which is required when specifying the other field. The seconds field fires with sub-minute precision, enabling patterns like 0/30 * * * * ? for every 30 seconds.