McALLEN The first day of classes for the 2011-12 school year will be Monday, August 22. In the new school calendar, approved by the McAllen School Board at its April 25 meeting, teachers will report back to work on Thursday, August 11. The fall holidays include Labor Day (Monday, September 5), Monday, October 10 (a possible weather make-up day or holiday) and Thanksgiving (Nov. 21-25). The winter break will begin on Thursday, December 22 and end when students return to class on January 10, 2012. Spring Break will be March 12-16 and the last day of classes will be May 31.