When does winter begin?

Winter begins from the solstice of winter.

The winter solstice is the 22nd solar term among the 24 solar terms in China, when the sun reaches 270 degrees of the yellow meridian. On the solstice of winter, the sun shines directly on the tropic of Capricorn, and the day is the shortest and the night is the longest in the northern hemisphere.

As early as more than 2,500 years ago in the Spring and Autumn Period, China had observed the sun with the earth, and determined the winter solstice, which was the earliest of the 24 solar terms, and the time was from 0 to 23 in Gregorian calendar 65438+February 265438.

Meteorological changes in winter solstice

The winter solstice has the shortest day and the longest night. After this day, the days began to get longer and longer. Therefore, the ancients believed that "the winter solstice is the sun, and the sun is quiet with the yin." In other words, the solstice in winter is a time when yin and yang alternate. From then on, Yin Qi began to decline and Yang Qi began to sprout, which marked the end of winter and the arrival of spring.

After the winter solstice, the climate in all parts of China will enter a coldest stage, which is often called "ninth year cold" and "ninth year cold". The so-called "number nine" refers to nine days from the date of winter solstice, which is called "nine". After nine nines, it happens to be 8 1 day, whether it is "nine out" or "nine out". From "September 19th" to "September 9th", the cold winter turned into a warm spring.

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