When in my 20 's and 30's - 8 hours.
Now, in my 60's - if I get 7, I'm thrilled.
Couple of years ago. "The Warden" was fighting cancer, again - I wasn't getting even 5 hours of continuous sleep a night.
Wound up going to sleep at the wheel, coming back from the place, and turned over a trailer and farm tractor!
THANK GOD - the only casualties were the trailer, pickup bed, and Johnnie (Deere)!