In Settings page, Scroll Down to Reach the Schedule Settings, Over there you can set the clinic working hours from and to timings, The Calender will start from the Earliest timing in the week and will end in the latest timing set for the week, for example, in the Given Image, the Earliest timing is 8 AM and the Latest timing is 10 PM, so the calender will begin from 8 AM in the Morning and end by 10 PM in the night every day.