See the academic calendar by semester:

• Spring Semester, 2010
  Monday, October 26, 2009 - Registration begins for spring 2010
  Tuesday, January 19 - Friday, May 7, 2010; Final Exam: Mon-Thu., May 10-13, 2010
• Fall Semester, 2009
  Monday, March 30 - Registration begins for fall 2009
  Monday, August 24 - Friday, December 11, 2009; Final Exam: Mon-Thu., December 14-17, 2009
  
• Summer Semester, 2009
  Tuesday, February 17 - Registration begins for summer 2009
  1st 8-week session runs Monday, May 18-Sunday, July 12
  2nd 8-week session runs Monday, June 8 to Sunday, August 2
  10-week session runs Monday, June 8 to Sunday, August 16
  

Also see published Class Schedules:

http://registrar.boisestate.edu/academic-calendar.shtml