cease to sleep longer than is needful; retire to thy bed early, that ye may not be weary; arise early, that your bodies and your minds may be invigorated.Doctrine & Covenants 88:124
Sleep schedules will vary from person to person and not everyone needs the same amount of sleep at the same time.
But it is best to have a consistent sleep schedule. Our bodies are also wired to go to sleep when it’s dark outside and to be awake when it’s light.
And adults need 7-9 hours a night.
For me personally, I don’t like staying up any later than 11:00, and usually I’m wasting time if I’m staying up past 10:00 or 10:30. I can’t consistently wake up earlier than 6:00 in the morning.
I know I need at least 7.5 hours of sleep to function, but I don’t need anymore than 8.5 hours. So I should at least go to sleep between 9:30 and 11:00 and wake up between 6 and 6:30. Optimally, I would go to sleep more towards 9:30 or 10:00 than 11:00.