By default, the day and week calendars show a full 24-hour period from midnight to midnight, but now you can change this and make the range of hours shown match your business hours. For example, your business may only schedule client appointments between 10:00 AM and 6:00 PM, so you do not want to have hours before 10 or after 6 shown on the calendar. To change the range of hours shown, go to Settings > Calendar Settings and adjust the sliders labeled Calendar Hours Range.
If an appointment is scheduled for a time outside of the calendar hours range, then a popup alert will let you know when you're on the appointment date.
Setting for Calendar Hours Range
Day Calendar showing hours limited to 10:00 AM and 6:00 PM