The Dongzhi Festival or Winter Solstice Festival () is one of the most important Asian festivals celebrated by the Chinese, Hong Kongers, Taiwanese, Japanese, Vietnamese, Koreans and other East Asian-related people during the Dongzhi solar term (winter solstice), some day between December 21 to December 23. The origins of this festival can be traced back to the yin and yang philosophy of balance and harmony in the cosmos. After this celebration, it is believed that days will have longer daylight hours and therefore create an increase in positive energy flowing in. The philosophical significance of this is symbolized by the I Ching hexagram fu (, "Returning"). Traditional activities Traditionally, the Dongzhi Festival is a time for families to get together. One activity that occurs during these get-togethers (especially in the Asia and in Overseas Asian communities) is the making and eating of tangyuan (汤圆) or balls of glutinous rice, which symbolize reunion. Tangyuan are made of glutinous rice flour and are sometimes coloured pink or green. Each family member receives at least one large tangyuan in addition to several small ones. The flour balls are cooked in a sweet soup or savory broth with both the ball and the soup/broth served in one bowl. It is also often served with jiuniang, a mildly alcoholic, unfiltered rice wine containing whole grains of glutinous rice (and often also sweet osmanthus flowers). In northern China, people typically eat dumplings on Dongzhi. This custom is said to have been started by Zhang Zhongjing in the Han Dynasty. One cold winter day, he saw the poor suffering from chilblains on their ears. Feeling sympathetic, he ordered his apprentices to make dumplings with lamb and other ingredients, and distribute them among the poor to keep them warm and prevent their ears from getting chilblains. Since the dumplings were shaped like ears, Zhang named the dish "qùhán jiāoěr tāng" (祛寒娇耳汤) or dumpling soup that expels the cold. From that time on, it has been a tradition to eat dumplings on the day of Dongzhi. In southern China, people eat rice cake (), which means reunion. It is not only eaten by the family, but also shared with friends and relatives as a blessing. Mutton soup, rice cake and red bean sticky rice are also popular in southern China. Old traditions also require people with the same surname or from the same clan to gather at their ancestral