Not sure what kind of answer you are looking for. That question is so general. Could think of something ah la Dr. Seuss, but won't write it in that form.
When would I like to have sex?
In the early morning, late morning, before lunch, after lunch during the afternoon, before dinner, after dinner, before bed... in the middle of the night...
When I'm in bed, when I'm thinking of bed, when I'm in the kitchen, when I'm in the lounge, when I'm in the office, when I'm in the car, when I'm on the beach, when I'm in a dressing room, when I'm with a sexy woman, when I wish I was with a sexy woman and possibly when I am thinking about just having been with a sexy woman.
Lots of different possibilities. But, as the previous poster so astutely observed, generally when I'm horny.
But, the other question was, when do I have sex?
Nowhere near often enough
How about you?