Winter Solstice dumplings, Summer Solstice noodles, and Sanfu pancake stalls with eggs.

Winter Solstice (English: winter?solstice), also known as "Winter Festival" and "Winter Festival", is one of the twenty-four Chinese solar terms and one of the eight astronomical solar terms, opposite to the summer solstice. The winter solstice begins when the sun reaches 270° of ecliptic longitude, which is around December 22 of the Gregorian calendar every year. It is said that the winter solstice was the New Year's Day in the Zhou Dynasty in history, and it used to be a very lively day.

On the winter solstice, the sun reaches the southernmost point of the year, almost directly hitting the Tropic of Capricorn (23°26' south latitude). The northern hemisphere gets the least sunlight on this day, 50% less than the southern hemisphere. The days in the Northern Hemisphere are at their shortest, and the days get shorter as you go further north.

The specific date of Sanfu is determined by the combination of the solar terms and the dates of the zodiac signs. my country's traditional calculation method stipulates that the third Geng day after the summer solstice and the fourth Geng day are the starting dates of Chufu (Toufu) and Zhongfu (Two Fu) respectively, and the first Geng day after the Beginning of Autumn is the last day. The first day of summer. Geng day is a day with the word "geng" in the zodiac calendar, such as Gengzi, Gengyin, Gengchen? Such dates are published in the "Rural Annals" every year.