Library

Great Cold, Beginning of Spring, Rain Water, and Awakening of Insects belong to spring; Full Grain, Grains in Ear, Summer Solstice, and Minor Heat belong to summer; Start of Autumn, End of Heat, White Dew, Autumn Equinox, Cold Dew, and Frost's Descent belong to autumn; Start of Winter, Minor Snow, Major Snow, Winter Solstice, and Minor Cold belong to winter. Counting from the beginning: The first period (Yun) begins thirteen days after Great Cold; the second period begins ten days after Grains in Ear; the third period begins seven days after End of Heat; the fourth period begins four days after Start of Winter; and so on.

[Note] Heaven uses Six Qi as its rhythm, dividing the twenty-four solar terms into six parts, corresponding to the six steps of the Six Qi. Earth uses Five Movements (Wu Yun) as its system, dividing the twenty-four solar terms into five parts, corresponding to the five positions of the Five Movements. Among the twenty-four solar terms, Great Cold, Beginning of Spring, Rain Water, and Awakening of Insects govern the First Qi; Spring Equinox, Pure Brightness, Grain Rain, and Start of Summer govern the Second Qi; Full Grain, Grains in Ear, Summer Solstice, and Minor Heat govern the Third Qi; Major Heat, Start of Autumn, End of Heat, and White Dew govern the Fourth Qi; Autumn Equinox, Cold Dew, Frost's Descent, and Start of Winter govern the Fifth Qi; Minor Snow, Major Snow, Winter Solstice, and Minor Cold govern the Final Qi. This describes when the Host Qi (Zhu Qi) and Guest Qi (Ke Qi) respectively govern the six time periods. From Great Cold until twelve days after the Spring Equinox, it governs the First Movement (Yun); from the thirteenth day after the Spring Equinox until nine days after Grains in Ear, it governs the Second Movement; from the tenth day after Grains in Ear until six days after End of Heat, it governs the Third Movement; from the seventh day after End of Heat until three days after Start of Winter, it governs the Fourth Movement; from the fourth day after Start of Winter until the last day of Minor Cold, it governs the Fifth Movement. This describes when the Host Movement (Zhu Yun) and Guest Movement (Ke Yun) respectively govern the five time periods.

The Host Movements follow the sequence of Jue (Wood), Zhi (Fire), Gong (Earth), Shang (Metal), and Yu (Water). The "Tai" (Excess/Superabundance) and "Shao" (Deficiency/Insufficiency) of the five tones are determined by the Central Movement (Zhong Yun). If encountering a year with Tai Zhi or Tai Shang, then the First Movement must be Shao Jue, the Second Movement is Tai Zhi, the Third Movement is Shao Gong, the Fourth Movement is Tai Shang, and the Final Movement is Shao Yu. If encountering a year with Tai Jue, Tai Gong, or Tai Yu, then the First Movement is Tai Jue, the Second Movement is Shao Zhi, the Third Movement is Tai Gong, the Fourth Movement is Shao Shang, and the Final Movement is Tai Yu. By taking the Guest's Central Movement to derive the Host's Tai/Shao generation relationship, and using the Host's Tai/Shao to determine the Guest's Five Movements, through the method of Tai/Shao overlapping, the principles of addition and proximity, as well as excess and deficiency, are elucidated.

[Note] The tones of the Host Movement necessarily begin with Jue and end with Yu, which is the regular order where the five tones respectively govern the four seasons and are distributed sequentially. However, Yang years are called "Tai," and Yin years are called "Shao," representing the variations of excess and deficiency among the five tones and four seasons. For instance, in a Wu year with Tai Zhi or a Geng year with Tai Shang, the Host Movement's First Movement is necessarily Shao Jue, the Second Movement is Tai Zhi, the Third Movement is Shao Gong, the Fourth Movement is Tai Shang, and the Final Movement is Shao Yu. In an Ren year with Tai Jue, a Jia year with Tai Gong, or a Bing year with Tai Yu, the Host Movement's First Movement is Tai Jue, the Second Movement is Shao Zhi, the Third Movement is Tai Gong, the Fourth Movement is Shao Shang, and the Final Movement is Tai Yu. Therefore, it is said that both "Tai" and "Shao" are derived from the Central Movement; this means using the Guest's Central Movement to determine the Host's Five Movements, illustrating the meaning of Tai/Shao generation. Furthermore, by using the Host's Tai/Shao to determine the Guest's Five Movements, applying the method of Tai/Shao overlapping, the principles of addition, proximity, excess, and deficiency are revealed.