How NetBackup determines the due time for each schedule

The due time is based on the last backup data for the schedule, plus the schedule's frequency:

Last backup data + frequency = Due time

The last backup data refers to the schedule that ran most recently among comparable schedules. NetBackup uses the date and time of that schedule to determine the due time for all the schedules that use that schedule as the last backup data.

In some cases, the last backup data for a schedule names the schedule itself. In other cases, the last backup data for a schedule is another comparable schedule.

Comparable schedules are those schedules that fit the following rules:

Full schedules are compared to other full schedules of the same or longer frequency.
Cumulative incremental schedules are compared to:
- Full schedules of the same or longer frequency.
- Other cumulative incremental schedules of the same or longer frequency.
Differential incremental schedules are compared to:
- Full schedules of the same or longer frequency.
- Cumulative incremental schedules of the same or longer frequency.
- Other differential incremental schedules of the same or longer frequency.
  
  Note:
  
  To have a longer frequency means that the schedule is configured to run less often.

The comparison rules ensure that no schedule is overlooked for consideration, potentially causing a gap in backup coverage.