Blocking off days when the business is closed for holidays are called 'Blackouts'. You can set blackout dates on the calendar page by pressing the button, located on the left, here:
This will launch a blackout dialog box that looks like this:
Enter the name of the blackout (such as "Thanksgiving Closure"), blackout type, start date/time, and end date/time for the blackout. There are three types of blackouts that you can set:
Merchant Blackout - Prohibits bookings for all activities and rentals for the entire business Typically this is used for business closures.
Product Blackout - Prohibits bookings for specific activities or rentals. Typically this is used if your mountain bikes (or other subset of equipment) is all out for maintenance at once... but you are still able to offer road bike rentals. When this blackout type is selected, a secondary dropdown will appear asking to select a specific product, it looks like this:
Unit Blackout - Prohibits bookings for a specific rental unit. This is used if a unit is broken and not adequate to be rented, such as a leaky kayak that needs to be fixed. When this blackout type is selected, a secondary dropdown will appear asking to specific the unit category and individual unit, it looks like this:
Then press 'Create' to save and establish the blackout. All blackout types will be visible on the calendar. Here is an example of a Merchant Blackout showing on the calendar for Monday June 1st.
Click on an item that is blacked out on the calendar to edit or remove it.