I do not use a channel manager but they charge a fee and they handle all your bookings from all the different sites you advertise on like BDC Airbnb TripAdvisor etc
To change calendar go into calendar and click edit and click on dates you want to open or show as not available.
A similar situation happened to me and BDC did not charge me twice record it as a no show and it should be fine.
I am very happy with the support I have received from booking.com
my guest arrived did not stay because I did not have air conditioning do they have to payhow can I be paid direct from bdc
2 bed chalet in gated community in falmouth Jamaica