I'm up at 5 pretty much every day. Of course I go to sleep about 9..
I've worked all shifts, schedules, days, 8-18 hours over the years, and get 6-8 hours of sleep a night(I'm blessed to have worked 1st shift, mon-fri for over 7 years now.
Regardless, I'm the most useless between 5am-9-10am any day, lol