There is a big difference between sleeping during the day and sleeping at night, mainly because the sleep effect is different. Sleeping at night is the result of long-term human evolution, in the evolutionary history of mankind, daytime has sunlight, in the face of various dangers of nature, daytime is conducive to people to observe the surrounding dangers, to protect themselves, and sufficient sleep at night can ensure sufficient physical strength, to facilitate the next day’s labor. Sleep at night is the best time for human cells to repair and renew themselves. Not sleeping at night violates the natural law and can lead to lower body resistance in the long run, resulting in mental symptoms such as memory loss, lack of concentration, irritability, anxiety, etc. It may also lead to organ and system imbalance, heart arrhythmia, endocrine disorders, decreased resistance, etc.