The earlier you take the DTP, the less risk of adding additional supression during pct. As long as you keep it around 6-8 hours before bed you should be ok. The reason for taking it in PCT is more to deal with cortisol build up, and protect muscle tissue during a normally catabolic time(after a cycle). Used on a cycle, you can dose it however, whenever to add test to your body via dhea, and pregnenolone conversion.
PCT is a time you don't want to risk delay of recovery. Def keep it to mornings during PCT, and hit up a few DTH like 2 hours before you lift. I find that DTH takes about 2 hours to fully kick for me. Depends on whats in your stomach.