According to an article in Daily News:

SEEING DOUBLE: Mary-Kate & Ashley Olsen have yet to reach their 18th birthday, but they show a more mature side in a photo shoot for the May issue of Allure. The twins, who began studies at NYU's Gallatin School of Individualized Study last fall, have a movie, "New York Minute", coming out May 7th.

whoa the olsen twins are growing up before our eyes.

They're not starting college until THIS fall.

http://www.eonline.com/News/Items/0,1,13141,00.html

There's a nice little link about everything.

They were accepted sometime around December of 2003....they start Fall 2004.