The End's Not Near, It's Here - S4-E16
Corrected entry: During the final montage the banners at Berkeley are welcoming the class of 2012. But this was fall of 2007, so four-year students would finish school in 2011.
Correction: If he graduates in 2012, then he is 24? (He is 18 in season 3, then 2007 he is 19? Also, Seth and Summer gets married the same year and therefore Sophie is five? She looks more like 7.
Correction: Ryan is in the architecture program. It is a five year program, so the year is correct.
At a freshman orientation, the welcoming banners are for the student body at large, not the small number of students who will be entering a five-year program. In addition, Berkeley's architecture program since the 1960s actually is not a five-year program, but rather a "four plus two," where students complete a non-professional bachelor of arts degree in four years, followed by a professional master of architecture degree after two more years. So that's four or six years, not five.