People sleep better without time pressure. Actually, I find consulting the clock a pleasure during the night. If I have still an hour of sleep before I wake up, it is a delight to go back to bed and know that I get one more hour of blissful rest. I realize that some people will have the opposite reaction. And herein lies the problem.
Sleep is a very unique activity.
Some people get by on just a few hours. Some people do just fine on three or four hours of sleep per night. Perhaps they would do better on eight hours, but they seem to do just fine on just a few. Apparently President Bill Clinton is one such person. Most people need about eight, and some need ten or eleven to feel good.