Set your working hours and your clinic's time zone in Settings. On-call and the phone menu use them to know when you're closed. Your hours and the schedule follow the clinic time zone, including when daylight saving time changes.
The suggested hours are only a starting point: save them to keep them.
Calls during working hours. You can send calls straight to your clinic's direct line while you are open, instead of paging the on-call team. This adds a repeating "no routing" block to your on-call schedule for each open day. You need a clinic direct line first; without one, callers would hear a closing message during working hours. If on-call shifts overlap your working hours, move or remove them on the schedule, then apply again.