1. The occurrence of spring, summer, autumn, and winter is a result of Earth's rotation and revolution around the sun.2. Earth's axis is not perpendicular to its orbital plane but is instead inclined at an angle of 23 degrees 27 minutes, causing the sun's直射點 to move between the Tropic of Cancer and the Tropic of Capricorn.3. The beginning of each season is marked by the Twenty-Four Solar Terms, with "Li Chun" (the Start of Spring), "Li Xia" (the Start of Summer), "Li Qiu" (the Start of Autumn), and "Li Dong" (the Start of Winter) as the respective starting points.4. The transition of spring to summer, summer to autumn, autumn to winter, and winter to spring reflects the pattern of Earth's movement around the sun, symbolizing spring growth, summer maturity, autumn harvest, and winter storage.5. The division of the four seasons is based on the changes in day and night length and the angle of the sun's radiation, with the solstices and equinoxes or the four solstice days as the boundaries.6. Different regions may use different points as the boundaries for the seasons.7. In China, the traditional starting points for the seasons are the four solstice days of the Twenty-Four Solar Terms, with the solstices and equinoxes serving as the midpoints.8. The solar terms of spring include Li Chun (the Start of Spring), Yushui (Rain Water), Jingzhe (the Awakening of Insects), Chunfen (the Spring Equinox), Qingming (Pure Brightness), and Gu Yu (Grain Rain).9. The solar terms of summer include Li Xia (the Start of Summer), Xiaoman (Grain in Ear), Mangsong (Grain Buds), Xia Zhi (the Summer Solstice), Xiaoshu (Light Thunder), and Dashu (Great Heat).10. The solar terms of autumn include Li Qiu (the Start of Autumn), Chushu (Beginning of Shade), Bai Lu (White Dew), Qiu Fen (the Autumn Equinox), Han Lu (Cold Dew), and Shuangjiang (Frost's Descent).11. The solar terms of winter include Li Dong (the Start of Winter), Xiaxue (Light Snow), Daxue (Heavy Snow), Xiao Dong (the Winter Solstice), Xia Han (Light Cold), and Da Han (Great Cold).12. The dates of the Twenty-Four Solar Terms are determined by the position of the sun along the ecliptic, reflecting the changes of the seasons.詳情