There are short-sleepers and long-sleepers.
Short-sleepers need as little as five and a half hours.
Long-sleepers need as much as about nine and a half hours.
Thats means that the short-sleepers can get 2 months more work done than long-sleepers - every year! or in their entire lifetime its more than 12 years!!!
If you are long-sleeper, but know that you have the inherited genetic needed to become a short-sleeper, then improve the quality of your life (less stress, better diet, reqular exercise, and more exposure to light).
You will then always be ahead of the rest