Cron trigger
Cron triggers allow you to schedule the recurrent execution of a management action at particular time intervals within a particular time slot. The required time sequence is declared using a cron expression.
For example, if a rule that contains the relevant management action must be triggered every hour in the period from 2:00 AM to 6:00 AM included, the cron trigger should be defined as 0 0 2-6 * * ? .