If your servers recognize Daylight Savings Time (DST), jobs scheduled using simple recurrence may seem to occur one our later (when DST ends) or one hour earlier (when DST begins). In the example below this job is scheduled at 11:18 am, in October when DST begins the job will run at 10:18 am. This is because the simple scheduler simply adds 24 hours to the last run time not an entire day.
If you want jobs to recur at the same time of day and respect DST adjustments use the Calendar Recurrence
- Timezones in JasperReports Server
- Section 3.4.5 Specifying Job Recurrence in the JasperReports Server User Guide