As a professional procrastinator I would suggest craming now. I've tried the morning thing and it just doesn't cut it. I found, for myself, that studying in the morning made me even more anxious about the test and making sure that I was absorbing what I was studying. I say start studying now, girl!!! Shut the computer off and hit those books. Leave yourself at least four hours to sleep. Study tonight, get some sleep, then get up and ace that test!!!
Good Luck!!!