My general guideline for exams, is that they should exist only through the mention or role-play. They aren't necessarily required in action. If, however, instructors feel a need to make and carry out exams, go on right ahead.
I recommend keeping a short list of who attends classes. The minimum an instructor should do is take note of who participates and pass/fail them on that. If an instructor wishes to toss out a few assignments and grade upon that measure, then that is acceptable as well.
Quarters last a month. But how long is an RL month in CD time? I can't say. There's never been an established time ratio for the Crack Den. Just keep in mind that CU's a very liberal college that carries out duties in a very unorthodox way.