Apertura runs from early august to late november (that's not counting preseason or playoffs, both of which run at least 2 weeks) and then the clousura runs from early january to july (again not counting pre and post season.)
8 teams with 2 from Mexico, 2 US, 3 Central America and 1 caribean is MUCH MUCH MUCH better than the 2003 format of 16 teams. thank you for your info el charro.