Similarly I had a Hampton Inn in Lincoln Nebraska booked for the night before I actually needed it--my mistake. I realized this after 6 PM on that night and phoned the HI directly explaining what I had done. They gladly honored my stay for the next night. Now it was not a busy time and I could understand if they turned me down if they were full and could have sold more rooms. Glad that it has usually worked out for me. At a minimum, I have received points for the stay and stay credit on another occasion (Hilton Beijing, flight cancelled and unable to get there).