<p>There’s typically class for other nights of the week so if you’re trying to combine a bunch of classes (consisting of a large number of students, like 100+ people) together for a general exam, one of the most available times that can work for everybody is Friday night if they’re not willing to go into the weekend. You should learn more about the circumstances in which the exam was given. Most likely, the professor would not have done it if there were other times available. Also, academics take precedence over social events, especially when exam times are published AHEAD of time and people with conflicts could re-schedule their other engagements that conflict with the exams. Students who are sick or can’t attend for religious reasons are excused and are scheduled for a make-up version. If they were actors in a performance, I’m sure that is also excusable.</p>