Why is the winter solstice the shortest day?

On the solstice of winter, the direct sunlight on the ground reaches the southernmost point of the year, that is, the sun is directly on the tropic of Capricorn, and the sun is most inclined to the northern hemisphere. Therefore, the winter solstice is also the year with the shortest day and the longest night in the northern hemisphere all year round. After the winter solstice, the direct point of the sun slowly moves northward, and the days in the northern hemisphere gradually lengthen and the nights gradually shorten.

China measured this solar term as early as the Spring and Autumn Period and applied it to agricultural production. During this period, in addition to continuing to prevent freezing and accumulate fertilizer, we also pay attention to protecting farm animals for the winter.

Ethnicity

During the Zhou Dynasty, there was a ceremony to worship the gods, and in the Han Dynasty, it was listed as an order festival, which was a custom to celebrate festivals. During the winter solstice in Wei and Jin Dynasties, the emperor was greeted by hundreds of officials and presented with socks and shoes, indicating that he "welcomed good luck and practiced longevity". In the Southern and Northern Dynasties, it was more important than before, and there were ceremonies to worship ancestors and mothers. There is a folk custom of eating red beans to ward off evil spirits.

In the Tang and Song Dynasties, the winter solstice and the beginning of the year were the most important, and this custom was still inherited in the Ming and Qing Dynasties. The custom of winter solstice varies from region to region. In Guangdong and other places, people make powder cakes before winter and rice cakes for the Spring Festival, which are called "powder before winter". It is dried white rice, which is also called "dried winter rice". It is said that cooking porridge for patients can accelerate recovery. Make a "winter solstice circle" with glutinous rice flour, which is called "adding years". Knead glutinous rice flour into various small animals and steam it to make toys for children.

Before eating "winter solstice yen", stick a circle on the back of doors, windows, tables, cabinets, beds, lights, etc. , that is, the so-called "cost", and then put it on the stove and then take it down for baking to predict whether it "swells". Eat jiaozi in pairs. If there are two tablets left in the last spoonful, everything will be fine for the married and everything will be fine for the unmarried. In the evening, the whole family burned incense to their ancestors with three fruits and had a feast.

In addition, it is fish, raw clams, vegetables and so on. There is a habit of eating raw fish (sashimi), which is called "raw fish in winter and dog meat in summer".

Reference to the above content: People's Daily Online-Twenty-four solar terms | Winter solstice