Mark -
My prescribing physician initially told me to split my Pred dose (am/pm) but 6 mos later, during my wean, my endocrinologist (he oversaw the taper process) said that was a mistake.
He said for future reference to always take Pred around 7am as it most closely mimics the body's natural cortisol production and will help prevent adrenal fatigue. Not sure if all drs support this but worth asking.
As for Pred, in general, I remember thinking, "sleep....what's that?!!?"....
Best of luck.