Retiree and I am always up by 4am at the absolute latest and usually it is anywhere between 2 and 3am. But I do go to bed at 8pm so there's that. Habit from my working years and I enjoy the peace and quiet. Me and the dog up while the wife sleeps in until 6am when she gets up for work.
I tested this last year when I moved into a new place having been up all night.. went to bed at 19, and woke up at 3 AM. From there I kept it going throughout the year.
I used to enjoy being up late for the peace and quiet but damn, you can rather get that in the morning AND feel good about it at the same time