im pretty sure its eastern BUT its not always at midnight. i received mine at about 7:20 am while i was on the wards, i had other friends get it at 3 am, 4 am, 1:30 am.....it seems to be on some system that i am unfamiliar with.
moral of the story = DO NOT do what i did and stay up after midnight hitting refresh an awkward # of times. sleep and wake up knowing most likely your result is waiting for you
best of luck!