According to qigong Theory, the natural world and vital activities un-dergo cyclical changes in step with the shifting balance between yin and yang. Therefore qigong practice should be adapted to different times of the year. Each of the twenty-four solar terms defined in the Chinese lunar calendar has a unique state of yin-yang balance. The dates at the begin-ning of each term are important times for qigong practice, and different exercises can be used to suit the specific yin-yang balance of each term.
The yin-yang balance of the solar terms can be represented by hexa-grams. Dongzhi (Winter Solstice) is fu, with one yang line; Dahan (Great Cold) is lin, with two yang lines; Yushui (Rain Water) is tai, with three yang lines; Chunfen (Spring Equinox) is dazhuang, with four yang lines; Guyu (Grain Rain) is mei, with five yang lines; Xiao-man (Grain Full) is qian, with six yang lines; Xiazhi (Summer Solstice) is hou, with ene yin line; Dashu (Great Heat) is dun, with two yin lines; Chushu (Limit of Heat) is pi, with three 3n'n lines; Qiufen (Autumn Equinox) is guan, with four yin lines; Shuangjiang (Frost's Descent) is bo, with five Mn lines; and Xiaoxue (Slight Snow) is kun, with six yin lines.
