Sims don't sleep through the entire night
My Sims go to bed an sleep until the need is full and then wake up, whathever the time it is in the night. I remember they used to sleep at least until 6am before.
Forum Discussion
better beds fill up needs sooner so if you're using like a really good bed they only need a few hours of sleep, if their energy is full it doesn't matter what time it is they're going to get up. you want to put them to bed with the amount of sleeping time they need in mind
