HOW MANY HOURS DO YOU SLEEP PER DAY?

I used to sleep around 4-6 hours a day but it really killed my productivity during the day: I felt way too tired to do anything and like dozed off whenever I was working on anything, but I now hover between like 7-8 hours a day. I'm pretty sure the recommended amount of sleep for adults should be around 8-10 hours per day though.

Actually, how you you even function during the day off of 3-4 hours of sleep? Do you feel tired at all?