Not really as nine hours of sleep is good for you. Gives your body and mind time to rejuvenate itself. Feel lucky that you can sleep that long as it seems the older you get, the less sleep you get.
Is it bad to sleep at 9 and wake up at 6?
9 hours is good but you don't state your age, but this is a really good amount for anyone so youre doing good here.
I usually go to bed sometime between 10 and 12 and wake up at sometime between 7 and 8....
No its not bad. You're getting enough sleep.
In my opinion, I think this is a very good habit, this can keep you enough sleeping hour, only you have enough sleep can you have full energy. So I think this is a good habit.
I can tell you if you do like this ,then your skin will be better and looks good than those who are not . Good sleep ,good health.