One year has four seasons: spring, summer, autumn and winter and it also has 24 solar terms as well. They repeat themselves. In 24 solar terms, the principle of unification of heaven and man is implemented. Adhering to the strength of heaven and earth, regulating the bodys meridians, the ancient Chinese calendar, according to the growth cycle of plants and animals, determines the season, and it is the worlds richest calendar with a wealth of scientific connotation. Sima Qian pointed out incisively: ""Sowing in spring, growing summer, harvesting in autumn and storing in winter are the great truth in the heaven and earth. If we dont follow such rules, nothing can be our discipline."" Therefore, people should know how to adapt themselves to climate change, conduct health care effectively and prevent disease attack. - from Amzon