In 2008-2010, fall break was Mon/Tues. In 2010, they moved it back a week so it was the M/T after we played at Houston instead of right after we played Alcorn at home. In 2011, there was no fall break, and they gave us the whole week off for Thanksgiving. In 2012, the UT game was supposed to be played on Thursday Oct 11, but they moved it back to Saturday. According to the revised calendar for fall 2012, classes were either going to be canceled all/part of the day for the game, and fall break was going to be lumped into the Thanksgiving week.
So yes, the school calendar can easily change for football. Most teachers canceled class if it started after 2pm or so for the Auburn game in 2010 because all the gameday parking rules went into effect at noon or 1pm. If you didn't like on campus, I believe the only place you could park was the Hump, and then ride the bus over.