Currently the NonAccessibleBlock only support StartTime & EndTime. Which make it impossible to different StartTime and EndTime on different days when view as WeekView (refer to attached screen captured).
Although the same result is achievable by using appointment to fill up those time slot. But, an extra code is needed to discard the selection when user tapped on those appointment. Furthermore, extra code is need to keep track of which time slot has been added as appointment.
Therefore, to support different start/end time of non accessible blocks in WeekView is definitely useful.