Nationally, our MIT period needs to be in between 4-10 weeks. Normally our chapter would choose 8 weeks, though spring semester we have two weeks of spring break, so it drags initiation out just a tad longer... but it's good to wait. ;)

pledge period and grades
 

ADPi has a 4-6 week pledge period. It has never seemed that this was inadequate in covering the essential material. It seems short now looking back, but when I was an Alpha, 6 weeks lasted forever. It was enough time for me to be certain that I loved the sorority (I was skeptical about Greek life as a whole) and to meet so many of the sisters.

It never hurt our GPA...we had the highest GPA on campus for like 5 years (I don't know about this past year since I graduated). There were times when our Alphas had a GPA higher than the sisters. We do have high grade standards during recruitment and we also had several academic things in place such as study buddies, study hours, etc. to help new members maintain their grades and adjust to college life.