A US Air Force General told my father that if a student takes more
than four years to graduate from college, then they will never be able
to go higher than the rank of Major.  My recruiter says that is not
true, but he is an enlisted man and this might be a criteria that
isn't published and only Generals know the answer to.  Or that USAF
General might not know what the current requirements are.  I am hoping
you have access to a General so you can tell me the right answer. 
However, my career is depending on this so if you can't find a
definite answer please don't put an opinion.
Thanks!