CSI: Law School

I've decided to keep up the grueling TV-watching schedule that I established this summer. I figure it doesn't really matter if I'm unprepared in class at the beginning of the semester - the professors will forget by the end of the semester. And I'm very responsible about doing some reading during every commercial break.

So I'm still catching up on my pop culture. How come I keep seeing ads for "season finales"? I thought TV shows ended their seasons in May. Maybe that's why the ads describe every single episode as "shocking".