In ancient times, based on agriculture and mulberry, living habits were formulated according to the long-term harvest of crops. For example, every day at sunrise, rest at sunset, and in the four seasons, it is spring ploughing and autumn harvest, and winter storage.

In the Yi-ology, this thought holds that the human body should follow the Heaven, and the cold and heat in the four seasons are caused by the revolution of the sun and the earth, so people should follow the natural changes. Therefore, spring and summer are the seasons when the sun's spirit grows, and when crops are harvested in autumn, the sun's spirit begins to shrink. People should hide and nourish the sun's spirit, and think that tonic in autumn and winter is conducive to the growth of the sun's spirit in the coming year.

In festivals, the 24 solar terms are generally used as a guide to work and rest, among which Yin Qi reaches its peak in winter solstice, Yang Qi is born, Yang Qi reaches its peak in summer solstice and Yin Qi is born. Tonifying should also be done step by step, mainly with warming.

Sociologically speaking, after harvesting in autumn, the ancients could not continue sowing in winter, and often there was enough storage at this time. Moreover, because the ancient people were not productive enough, they needed to add more heat to spend the cold winter when it was cold.