Studly Hungwell, with a lot of oral steriods, people will plan their dosing through out the day, based on the steriods half-life so that way they're able to keep the doses away from night time. The one sure way to suppress your natural test levels is to be taking doses later at night. When you sleep, this is a perfect time for your body to rebound it's natural production of test while you're taking a break from your dosing of whatever PH or AAS that you're taking. Basically, staying away from night time doses just allows you not to supress your HPTA as much.