I get up at 4:30 am during the work week, so I usually go to bed at either 9:00 or when it gets dark outside, whichever is later. On the weekends, I go as early as 11:00pm, or as late as 3:00 am. If I'm out in the garage tinkering with something, I can completely lose track of time and have no problems staying up very late.
My wife goes to bed between 11:00-1:00, but she works from home and doesnt get up until 8-8:30 most mornings. Her weekend sleep times are usually earlier than mine. Sometimes I stay up late just to enjoy the peace and quiet, unless she goes shopping or out with a friend I literally never have the house to myself.
None of this really matters, we sleep in different bedrooms anyway, and have for the last 10-12 years. I used to snore... apparently I dont anymore and I've been invited back into the master bedroom if I want, but our schedules are so different now it wouldnt make sense and would end up being disruptive. Plus she lets the dog sleep in the bed, and thats a big no from me, aside from the fact that I seem to be our dog's preferred human so if I twitch or move at all, she plops down right by my face or up against me and I just cant sleep like that.