The best sleep time for different age groups is also different, and should be in accordance with their age scientific sleep. The appropriate sleep time for people of different ages is 11 to 14 hours for 1 to 2 years old, 10 to 13 hours for 3 to 5 years old, 9 to 11 hours for 6 to 13 years old, 8 to 10 hours for 14 to 17 years old, 7 to 9 hours for 18 to 64 years old, and 7 to 8 hours for ≥65 years old. Deep sleep can effectively repair the damage to our bodies from staying up late, and is by far one of the most scientific ways to improve life expectancy and ensure good health.