This is something I’m still trying to figure out, also. Prednisone stays in your body something like 15-30 hours (can’t remember exactly), so there is a lot of variability there that may be different for different people. For one person, they may need to take it 2/day and for someone else, only 1/day. I’ve read 2 different rationales for timing of dose. One: you should take it at bedtime so that it will be in your system before the normal 4 am adrenal surge and better suppress the adrenal gland. Or two: you should take it in the morning, closer to the time of adrenal surge and when you need it most. If you can determine generally how long it stays in your system (if you only take it once, in the morning or at night, do you get a significant slump in the afternoon?), then you can at least determine how many times a day you need to take it. If twice, then usually take a dose smaller than the morning dose in the early afternoon. Then I’d just try the timing of the larger dose (bedtime or early morning) both ways and see which makes you feel the best. For my daughter, when she’s in school she takes it when she gets up at 6 am, but during vacations when she sleeps late, I have her take it at bedtime.