How did the 24 solar terms in beginning of winter come about?

1, beginning of winter is one of the 24 solar terms of the lunar calendar and one of the traditional festivals of the Han nationality; The time point is between Gregorian calendar165438+1October 7-8 every year, that is, the sun is located at 225 degrees of the yellow meridian. At this time, the sun is located at declination-16 19, and the noon sun height in Beijing is only 33 47. After beginning of winter, the sunshine time will continue to shorten, and the height of the sun will continue to decrease at noon. During the period of beginning of winter, the Han people regarded winter solstice as beginning of winter. In order to spend the severe winter, it is necessary to supplement the dietary customs.

2. beginning of winter is not only the time to hold a grand harvest festival and feast, but also the season when the cold wind blows at first. There are customs and activities such as "October New Moon", "Qin Sui Shou", "Cold Clothes Festival" and "Harvest Festival". At this time, in the north, it is the winter months when the water freezes and the ground begins to freeze, but in the south, it is the weather of Xiaoyangchun.

Beginning of winter is an important festival in October. During the Han and Wei Dynasties, Emperor Tiandi personally led the ministers to welcome the winter weather, commended and supported the martyrs who died for their country and their families, asked the deceased to save their lives, and encouraged the people to resist the plunder and invasion of foreign enemies or evil bandits. Among the Han people, there are customs such as ancestor worship, feasting and divining the age of ancestors, so as to fulfill the obligations and responsibilities of future generations and pray for a good year for them in the coming year. Some customs in early winter have been changed, and some have been passed down to this day.

4. As early as the Spring and Autumn Period and the Warring States Period, China was able to determine the four solar terms of winter solstice, summer solstice, vernal equinox and autumnal equinox by measuring the length of the midday sun shadow with a soil gauge (a pole was erected on the plane). 1 year, the shortest day at noon is the summer solstice, the longest day is the winter solstice, and the shadow length is the vernal equinox or autumnal equinox. By the Qin and Han Dynasties, the complete concept of the 24 solar terms had been formed.

5. In ancient times, 1 year was divided into 12 months, and each month had two solar terms. The former is solar terms, while the latter is neutral. Later generations collectively referred to solar terms and neutral gas as solar terms.

6. As can be seen from the naming of 24 solar terms, the division of solar terms fully considers the changes of natural phenomena such as seasons, climate and phenology. Among them, beginning of spring, Changxia, beginning of autumn, beginning of winter, vernal equinox, autumnal equinox, summer solstice and winter solstice are used to reflect the seasons. The vernal equinox, autumnal equinox, summer solstice and winter solstice are divided from an astronomical point of view, reflecting the turning point of solar height change. Beginning of spring, Changchun, beginning of autumn and beginning of winter reflect the beginning of the four seasons.

7. The time when the sun runs along the longitude of the Yellow River from zero degrees 15 degrees is called "a solar term". It runs 360 degrees every year, and * * * experiences 24 solar terms, twice a month.

8. In early winter, the longitude of the sun is 225 degrees. Traditionally, our people think that this day is the beginning of winter. Winter, as the end, means that after a year of field work, crops will be harvested. After beginning of winter passes, the middle and lower reaches of the Yellow River in China will soon freeze, and farmers from all over China will gradually turn to farmland water conservancy infrastructure and other agricultural activities.