My flight and hotel were booked together, leaving on the 18th and returning on the 20th, however my arrival wan on the 19th, so it made no sense to book two nights, so I changed my arrival at the hotel reservation to the 19th. However, Expedia still booked two nights (!) from the 19th to the 21st, even though my return was on the 20th.
I did not realize any of this until I arrived at the hotel on the 19th. I even had written them with my arrival and departure dates to request for airport transportation and they did not advised me about the miss match on the travel and booking dates.
Even so, the hotel shrugged at this and charged me for the full two nights (!)