These calculations have been made considering average human life span to be 50 years.
Adults sleep for about 8 or more hours per day usually. This means we spend about 1/3rd of a day in sleep.
Time spent in sleeping per day = 1/3 day
Time spent in sleeping per month = 1/3 x 30 = 10 days
Time spent in sleeping per year = 12 x 10 days = 120 days = 4 months
This means in one year we spend 4 out of 12 months in sleep. And in 50 years we spend 4 x 50 months in sleep which make about 16.7 years.
Now if we reduce this amount to 6 hours per day.
Time spent in sleep per day = 6/24 day = 1/4 day
This way time spent in sleep for 50 years will be 12.5 years. So you are adding more than 4 years in your life.
Some people might complain that this much sleep is not sufficient for them. There is a solution for it as well. Taking a short nap at noon between 12:00 to 16:00(4 pm) will make you fresh even if you sleep for like 5 to 6 hours at night. The ideal time for afternoon nap can be between 20-50 minutes. After this nap you'll feel completely fresh.
Moreover the night sleep should be managed according to the sleep cycle which lasts for 90-120 minutes . Details about sleep cycle and its management would be posted soon on the same blog.
