Well i know it has worked for some couples to plan a sex-night. If they've been caught up in stuff and have had little time to themselves, they might schedule a night of sex-reunion after such a long time of abstinence, both will be excitingly looking forward to it
But if you're now talking og having sex on the list on a daily basis, as "one of" the routines, then their sex life to me is as well as finished 
My gosh, the thing will get so boring and tiresome after a while, not to talk of whetever happened to sex also being a spontaneous act . .
So if the lady wanted her husband so so badly on tuesday night, rolling towards him or making a move in the living-romm, he''ll be like "but honey, its not yet thursday, remember this week sex fell on thursday"" i hope that's not what you meant though because
GEEZ, that's asking for too much ooh, not an option in my dictionary, at all
