need, no. but fairly often, it happens that there's a class that I want to take, but think won't fit, that it turns out would if I flipped my schedule around.
I'm half trying to solve that issue, and half think it's an interesting problem to see if I can come up with some sort of "optimal" schedule given requirements (doing a double major), class time preferences, and class ratings (this one's the bigger one, esp. with electives).