To add any unavailable dates go to Settings > Unavailable dates.
Here you will be able to select certain Appointments, Packages and Area Bookings and mark certain dates as unavailable online.
This allows you to make certain dates unavailable for bookings. This is not setting availability rules for your appointments/ packages, that is done in individual settings.
To mark any unavailable dates, select the type of offering then select the Appointment/ Package/ Area booking you want to mark with an unavailable date.
To find the date, you can move between the arrows to change the months of the calendar. You can press 'Go to today' to immediately revert back to the month you are in. When you have found the day you want to make unavailable, select the 'x' and that day should turn from green to red. You can select/ unselect dates as unavailable and the calendar will change accordingly.
Once your unavailable dates have been selected for a certain offering, when a customer goes to book this on your shop front (if bookable online) these dates will not be available.