The best time to take an SAT II Subject Test is, of course, right after you’ve finished a yearlong class in that subject. If, for example, you take a physics class in tenth grade, then you should take SAT II Physics near the end of that year, when all the material is still fresh in your mind. (This rule does not apply for the Writing, Literature, and Foreign Language SAT II tests: it’s best to take those after you’ve had as much study in the area as possible.)

ETS usually sets testing dates for SAT II Subject Tests in October, November, December, January, May, and June. However, not every subject test is administered in each of these months. To check when the test you want to take is being offered, visit the College Board website at www.collegeboard.com or do some research in your school’s guidance office.

Unless the colleges you’re applying to use the SAT II for placement purposes, there is no point in taking SAT II tests after November of your senior year, since you’ll get your scores back from ETS after the college application deadlines have passed.