Which solar term is beginning of winter? . . Thank you, everyone.

The winter solstice is a very important solar term, and it is also a traditional festival in China's lunar calendar. Up to now, there are still many places where the winter solstice festival is held. The winter solstice is commonly known as "Winter Festival", "Dragon Solstice Festival" and "Asian New Year Festival". As early as 2500 years ago, during the Spring and Autumn Period, China had determined the winter solstice by observing the sun through the soil return, which was the earliest of the 24 solar terms. The time is between February 22nd and 23rd of Gregorian calendar 12. The winter solstice is the year with the shortest day and the longest night in the northern hemisphere. After the solstice in winter, the days will get longer day by day. The ancients said this about the winter solstice: As soon as the cathode arrived, the yang began to grow, the sun went south, the day was short and the shadow was long, so it was called "the winter solstice". After the winter solstice, the climate everywhere has entered the coldest stage, which is what people often say. There is a folk saying in China that "it's cold in March and hot in dog days". According to modern astronomical science, the sun shines directly on the tropic of Capricorn from the winter solstice, and the sun is most inclined to the northern hemisphere. The northern hemisphere has the shortest day and the longest night. After this day, the sun gradually moved to the north. In ancient China, people attached great importance to the winter solstice and thought it was a grand festival. There is a saying that the winter solstice is as big as a year, and there is a custom to celebrate it. "Han Shu" said: "The sun shines on the winter solstice, and you are long, so congratulations." People think that after the winter solstice, the days become longer and longer and the sun rises. This is the beginning of a solar cycle and an auspicious day, which should be celebrated. The Book of Jin records: "On the winter solstice of Wei and Jin Dynasties, people from all over the world celebrated ... its appearance was not as good as that of Zheng Dan." Explain the ancient emphasis on the winter solstice.