Ah, that's a much different case. There's a (true) horror story about an upper division physics course at Harvey Mudd. It was an unlimited time proctored exam

Ah, that's a much different case. There's a (true) horror story about an upper division physics course at Harvey Mudd. It was an unlimited time proctored exam. The prof apparently expected the students to spend 4-5 hours, but when nobody had left by then he had to order some pizzas to feed them. If I remember the story correctly, most of the students exceeded 20 hours and, I might be making this up, but I believe a couple got into the 40-some range. This isn't really the usual case (most of the unlimited time exams are take home exams rather than proctored), but it's still terrifying.