I always find the booking dates on AIRBNB very confusing in regard to is it nights or day of arrival and day of departure. Im pretty sure its the latter but I cant fathom why its not made clear when you pick the dates ( like every other accommodation booking company) rather than latter on.
As a guest you just pick the check in date and the check out date so it is very simple.
As a host (if for example blocking dates) it is nights that you block so blocking the 20th of a month means no check in on 19th but check in is possible on the 20th.
Other booking site explicitly say arrival date and departure days and then how many nights you have booked before you press the booking button - just google airbnd booking dates and you will see there is confusion
As a guest you just pick the check in date and the check out date so it is very simple.
As a host (if for example blocking dates) it is nights that you block so blocking the 20th of a month means no check in on 19th but check in is possible on the 20th.