Coming from someone who just finished first year Science...
Biology and Chemistry tests are on Friday nights (since so many people are in these courses, Friday nights are the only time when there's enough space on campus to accomodate so many people writing at the same time). With 2 chem term tests, and 3 bio term tests (one of them being a lab test), that's 5 Fridays each term that you're going to have a test on. The plus side is (particularly if you're in res) that you're usually done by 9 or 930 at the latest, so you still have tons of time to get your weekend started on a high note
Calculus I had 5 tests, every other week, on Tuesday nights. These were only an hour long. Calc II had 2 tests, which were longer, but also on Tuesday nights (I think!).
Physics....I only took 1B03, but that had 2 tests, one on a Wednesday and one on a Thursday, but were only an hour long.
Psych I and II each had a midterm, one written in class, and one on a Tuesday night.
My elective was a social science, and that test was written during lecture time.
Basically, first year science has a ton of tests. I had one brutal week during first term, with a calc test, a physics test, a chem test, and all the regular lab and class work in one week. Unlike high school, when teachers might move tests around to accommodate tests in other courses, profs usually work around their own schedule when scheduling tests. It's during times like these when you realllyyyyy need to hope that your time management skills are at par (or work at getting them there!
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Oh....and quizzes are mainly done online (for bio and chem at least), and you have a set amount of time to complete them at your own pace before you aren't allowed to access them anymore. But there isn't going to be anyone to remind you when they're due, so it's usually a good idea to take a stab at them when they first become available, so that you aren't stuck struggling with concepts at 1145 when the quiz is due at midnight.