Is sleeping at 9 PM to 5 AM healthier than sleeping at 3 AM to 11 AM?

@benjaminion - I think you ask a good question but feel it's probably different for each person. I used to stay up late but was always up early I just had less sleep. Being a lot older has changed my thinking some and I'm pretty much in bed by 8 every night and up at 5 every morning. This seems to work OK for me but I know it is not a one size fits all thing. Here's an article that answers some of your questions and provides some things to think about.

What's the Best Time to Sleep and Wake Up?: https://www.healthline.com/health/best-time-to-sleep

I would LOVE more answers to this question, because as much as I have tried I can't seem to get my body's Circadian Rhythm to change from 3am to 11am. When 3 am hits, my eyes automatically want to close & my body wants to go to sleep, but prior to that, nothing, no matter what I do. To change it at all I have to stay awake for a full 24 hours to Reset my sleep cycle, but even that only lasts for awhile & I end up right back to the same time for sleep, 3 am. I feel rested after I sleep 3-11 & I enjoy my hours of midnight to 3am when the world is mostly asleep & I get total peace to do whatever I want or need without interuption. lol I love this time of day, for me. But I too get greif from doctors & health professionals that this isn't good for me, it's unhealthy. So I'm VERY curious, how is it for the rest of you? (R U called an insomniac if u don't sleep "normal" hours?)

Welcome Kelly @kellyaward, The member who started this discussion sadly has only posted 2 different discussions and has not returned. As one who used to be a night owl which for me seemed to start after working a third shift job in my younger days, I can relate to the difficulty changing sleeping habits. I did see an interesting article you might find helpful.

"Get light early in the day - According to the Centers for Disease Control and Prevention (CDC) , getting bright light early in the morning will help shift the time you start getting sleepy to earlier in the evening. Avidan recommends light exposure for 45 minutes to 1 hour each morning. Light intensity matters."
-- Tired of Being A Night Owl? 9 Steps to Stop Staying Up So Late
https://www.healthline.com/health/sleep/how-can-i-stop-staying-up-late
I think it was my 3rd shift job working from midnight to 8am for six months that made me realize what I was missing. Going to bed Saturday morning and then getting up late afternoon to have some fun and activities seemed great at first. But then it was a total drag Sundays when I had to go to bed in the afternoon so that I could be ready for work at midnight.

Are you still working or do you have regularly scheduled activities or hobbies you enjoy that might help you change your sleeping schedule?

Thought I'd add this to the discussion...

Oddly enough in medieval times there was the concept of "two sleeps". Originally this was two sessions of sleep at night separated by an hour or two between them. Some cultures had/have a variation of this which involved a longer night-time sleep followed by an afternoon nap.

Now it's called biphasic sleep or polyphasic sleep and has multiple variations. Some think it can be helpful. Here's a link for more information:
https://www.sleepfoundation.org/how-sleep-works/biphasic-sleep
I have to get up several times a night due to nature calls because I had my colon removed and back/hip pain - so I'm triphasic with very short 1-15 minute disruptions. Often I have wondered what would happen with overall sleep quality if I extended those disruptions to 30-60 minutes. That would require either starting earlier or sleeping later.

It seems to me sleep cycles change with age for most people. Young people need some morning hour sleep. I was more of a night owl as a younger person. As I’ve aged, that has shifted. I am alert until about 11:00 pm, but I’m waking about 6:00 am.

When I was younger, I’d be awake until at least 1:00 am, and could sleep until noon if it was not a workday. Oh, to sleep like that now! I was in excellent health.
I do believe a regular sleep schedule becomes more important as we age. We get by with a lot in youth!

I’ve been a night owl since childhood but of course had to get up earlier than I wanted in order to go to school (except during summer vacation), and later, had to get up early for work for over 43 years, often taking a nap in my car during my lunch hour to make up for loss of sleep. Now, in my early 70s I have issues with insomnia and also with sleeping for 2 hours then waking up wide awake and up for 2 hours, often more than once during the wee hours. I downloaded a free app called Insomnia Coach. It was created for the military but is open to all. Ironically, after doing the tracking and such for I think it was a week or two weeks, its recommendation was that I should go to bed at 3 AM and arise at 10 AM (7 hours). So there you go! I have been able to slowly get that back to 1 - 1:30 am but I rarely sleep more than 5-6 hours and then take a 1 hour nap (setting an alarm) when I’m able to do so in the afternoon. Being retired, I usually can do that. The only thing however, that has helped me not get up 2 or 3 times during the wee hours for a long period of time is to take one, 100mg gabapentin…an extremely low dose, around midnight. I guess it relaxes my body during the night enough to help it stay asleep, or, if I get up to go to the bathroom, I can go back to bed and go back to sleep. If indeed, I have to just get up, I only seem to need about a half hour to get sleepy enough to go back to bad and back to sleep. (Gabapentin at higher doses does me in with side effects. I’m happy to take a dose that shouldn’t work but does for me, and maybe it’s the placebo effect but since I’ve always been sensitive to medication, I think it’s just what works for me. Helps my restless legs in the middle of the night too.)

It’s taken a long time to work this out for me. Also, a great book called Say Goodnight to Insomnia by Gregg D. Jacobs has been invaluable. He says anything over 4 hours of sleep “can” be adequate. Makes me feel better about not being able to sleep more than 6 hours at most, overnight.

I love the quiet time after 11 PM also. I knit, crochet, do English Paper Piecing, read, play online games and puzzles…It’s almost as if I need that quiet time to myself to be able to sleep. I’m an introvert and perhaps the busyness of the day has to be set aside for me to be able to sleep.