To set your business hours go to the Availability page
My Business Name > Business Setup > Availability or Staff & Availability
On the Staff & Availability page, you'll be able to set up your own, or staff members availability by clicking into the corresponding profile you would like to update availability for.
Once you've clicked into the profile, you'll be able to scroll down until you see "Location and Hours". You'll then be able to set up the business or staff members' hours.
If you would not like regular business hours displayed on your MyTime profile, simply select 'By Appointment Only" and your listing will state that you are By Appointment Only.
Example below:
