Three hours? honestly wouldn't make a difference. Time isn't a factor in stopping anybody from finishing anything in time. With three extra hours we all would still be just as rushed. We procrastinators would say something along the lines of "well now i have so much time i don't need to do it now." People who actually get work done "on time" would have three hours more work to make them just as busy. Time is different for us all.
Someone who is constantly doing something, will find something else to do to fill there time, someone who wouldn't normally be doing anything would still.. be doing nothing.
I would be saying to myself, oh yeah well let me finish this, less important, thing now, and work on that big project with my extra hours. but.. in all honesty-- they wouldn't be extra anymore.