I dont think the time of day really matters much.
What does matter is that you inject on the same days and keep it consistant.
Once the AAS is in your system you want to keep your hormonal levels as constant as possible.
I know guys who inject right before they train but i think that may be more of a mental thing than anything else.
LOL bro you will sonn find out the last thing your gonna have to worry about is LOSEING you sex drive ON cycle...........put it this way every time my wife catches wind im starting a new cycle i hear "ahhh shit.....i cant DO IT all the time!" lol
With the Eth and Cyp esters, I shoot Monday/Thursday. Generally take the shot around the early evening when I get home from work and right before the gym. A couple hours difference isn't going to be a big deal, just try to keep it on the same days.