Sleep a person needs is really important. Beyond the simple "I am tired, I sleep now" from age two to ninety two, there are really good health and better thinking from getting enough sleep. From a medical, scientific, psychological point of view, sleep is essential for better cognitive skills and higher learning. If you can get 8 hours of sleep that is great.
For people who have irregular work schedules, or distractions, regular sleep might be lacking.
If is possible to sleep when you are tired, usually that is at night between 10pm and 6am for most people, great!
Was thought from medical science research studies, that humans need six to eight hours of sleep a night.
But now that research reports at least eight hours of sleep is needed for good health.
Aside from health for people who watch tv, listen radio, read magazines, use computer, play games, there are also many stories and folklore to do with sleep, night, time of day, dreaming.