Hello,
Technically they are perfectly within their rights to charge as accomodation is charged by the day or month which starts at 0000 and ends at 2400. IF you cross the line you pay simple. The argument has already been had and won in court that a tenant has a right at 0001 to access the room/flat/house ie the next tenant could legally come and kick you out of bed or alternatively jump in
Hotels are very different in that they charge you per 22 hour days, with an offset start time, unless you stay more than one night. They "usually" start their day at 1400 and end it at 1200.
Richard