Ummmmmm, yes. We were doing that Oprah/Dr. Laura Berman/plan your couples date night thing (unevenly and seldom successfully) for about 2 years. Why do you ask -- were we not supposed to?
Well, sounds really boring to me...just saying.
I can't recall ever contemplating an hour prior to getting it on, what the game plan would be...it just is not how it works.
Actually you would think that planning something would take away the excitement of it but reading up on this topic, it seems the opposite is actually observed.
Example: you plan for and have weekly back massages at the massage therapist for an hour every friday afternoon. You know about this appointment, the great feeling you derive from it and it doesn't take away the excitement of it. In fact it adds to the excitement, the anticipation builds, you start to think about this appointment on monday, tuesday, wednesday, thursday, etc...
Spontaneous sex sounds awesome (and it is) but planning sex for busy couples, say for once or twice a week at an agreed upon time gives people something to look forward to, it's possible they also put extra special care in their personal hygeine, wear special outfits, maybe even purchase a gift for the other spouse, etc.
Planning sex or other similar activities may sound boring but it turns out that people who do this have more satisfying sex lives than people who have spontaneous sex and are at the mercy of schedules that haven't allowed any time for this resulting in grumpy people who haven't had sex in a long time complaining about not having had sex in a long time.