Under settings, you will see the "Hours" tab. This is where you will set your permanent hours of operation, and which days you are open for business. If there is a holiday, or for whatever reason you may be closed on days that you are regularly open, you would edit those hours in "Hours of Operations change" found under the Availability tab at the top of the page. By going under this tab, you can go right to the specific week and edit the day/hours without having to play around with your set default hours.