I've always been an apologist of sleeping at least 8 hours per night/day and - except for my brief experiments with other types of sleep cycles - i have always tried to do so myself. I am one of those people that feels better when i manage to sleep around 8-9 hours per night, otherwise i already know that Saturday morning is going to be “wasted” sleeping :)
Now it turns out i was probably right: Some new studies have shown that 95% of people require at least 7 hours per night to function properly (i mean in an optimal way). From the remaining 5%, 2.5 require more than 7 hours. This means that only 2.5% of all people have an optimal sleep time of 7 hours or less.
So, i'm going to bed now :)