My department (math) features a lot of different talks and lectures and other events on a fairly regular basis, but they're always scheduled for late in the afternoon. Like 3 or 4pm.

Why do universities always do this? Do people really enjoy going to talks at like 3 pm? I assume it's because in the morning and early afternoon, a lot of students and professors are in class, but I think this is a silly norm to have in place.