Some properties like to overbook their occupancy for specific occasions or in case of no shows. This, however, could cause some issues in case there are still any displaced bookings to accommodate on that overbooked date. For this reason, some properties would prefer to disable the option to overbook once availability has reached 0%, including stays that have already been overbooked. This will ensure a positive experience for all guests as it will guarantee that you will have a space for every booking that was made for your property.
Jan Yung-Kuen commented
flexibility to open and close is vital