Welcome to the Dis... I am not sure about this, maybe you would like to email Disney to get the exact answer.. It would make sense since you are late check in that they do not charge you for that unused day, but maybe someone else can help here..........Also, just a word of advice here, we had a late check in one time and got an unsatisfactory room, we did change the next day after being awakened in the early AM by the grounds crew mowing lawns and running the leave blowers... just make sure if you have made requests for your room that they at least try to honor it... I believe the rooms are given out first come, first serve... so just a word of advice here.