The calendar display in the online booking engine offers little insight to customers as to why dates that appear available can't be booked. The greying out of dates when a property is closed for arrival or departure is ambiguous and can lead to potential customers giving up with their enquiry.
AirBnB handle this by displaying things like "host unavailable", or specifying the "minimum stay." See pictures attached. We have found that giving this information has seen potential customers have make contact to explore if there is potential for flexibility and proceed to make a booking as a result. It would be great to have this feature available for the direct booking engine.