<p>In my experience it has depended on the class. For my large lecture classes they made sure to tell us that all tests had to be taken on the day they were given, and if you missed it then too bad. They also made sure to tell us that if you had already boughten your ticket home and it conflicted it was not considered a viable reason to take the test on another day. However, for my Chinese exam the teacher was teaching multiple sections with the final on different days, and we were allowed to take it with any of the sections. Personally I’ve always left the day of my last final, even when it was an evening final.</p>