On the winter solstice, the sun moves to 270° of ecliptic longitude (winter solstice point). The position where the sun shines directly on the ground reaches the southernmost point of the year. The sun almost shines directly on the Tropic of Capricorn (also known as the winter solstice line). The northern hemisphere is most tilted. Therefore, the winter solstice is the shortest day of the year in all parts of the northern hemisphere, and the days get shorter the further north you go.

North of the Arctic Circle, the sun remains below the horizon all day long, making it the day with the widest polar night in the northern hemisphere of the year. Across the Northern Hemisphere, the winter solstice is also the day when the midday sun is at its lowest altitude throughout the year. As far as urban Beijing is concerned, the daylight on the winter solstice is only 9 hours and 20 minutes, and the height of the sun at noon is only 26°42'.

On the winter solstice, the northern hemisphere receives the least solar radiation, about 50% less than the southern hemisphere. The winter solstice marks the beginning of a new year. "Zai Jing Tang Ji" records that "on the autumnal equinox day when summer ends, spring comes into being at the winter solstice." The winter solstice festival is also the harbinger of spring. After the winter solstice, the night sky will completely change to the winter starry sky, and it will start to enter the ninth month from today. At this time, it is the hottest summer in the Southern Hemisphere.

Traditional food during the Winter Solstice?

Dumplings are commonly eaten in the north. Dumplings are an indispensable festive meal on the Winter Solstice of the lunar calendar every year, regardless of whether you are rich or poor. A proverb goes: "On October 1st, when the winter solstice arrives, every household eats dumplings." This custom was left to commemorate the "Medical Saint" Zhang Zhongjing who gave up medicine during the winter solstice.

Counting nine cold days

Counting nine during the winter solstice is a way for ancient people to calculate solar terms. Starting from the winter solstice every year, the day is counted as one, and the ninth day is counted as one, and the next nine days are counted as twenty-nine, and so on, until the end of nine-nine, spring comes.

The number nine on the winter solstice is also called "winter nine-nine", which is often referred to as the number nine in cold weather. The folk song "one nine two-nine, put your hands in your arms; three nine four-nine, freeze to death" Pigs and dogs; 5969, looking at willows along the river; 79 ducks and 89 geese; 7963, pedestrians putting on their clothes; 9981, an old man plowing in the field."