Why are the 24 solar terms so accurate?

Why are the 24 solar terms so effective?

This has to start with the origin of the 24 solar terms. This country has been a very developed country in agriculture since ancient times. Because of the close relationship between agriculture and meteorology, as early as the Neolithic Age BC, our ancestors began to observe the weather and climate. First, they observed the short days of the four seasons of the sun with earth gauges, and established a time system for years, months and days. In Shang dynasty, they used dry branches to record the days. In the long-term agricultural labor practice, the working people in ancient China have accumulated rich experience on the relationship between agricultural time and seasonal changes.

Twenty-four solar terms are a cultural heritage with great vitality in the ancient and splendid civilization history of the Chinese nation. They are tools to reflect the changes of weather, climate and phenology and to master the farming season. They were discovered, studied and created by Chinese ancestors after thousands of years of practice. The method of "seventy-two issues a year, with five days as one issue" appeared in the Zhou Dynasty. During the Warring States period, according to the astronomical scene of the first month and the phenological knowledge of birds and animals, such as the changes of tails and feathers, the days from winter to the sun (the year of the tropic of cancer) were divided into 24 solar terms. At the end of the Warring States Period, there were eight solar terms in Lu Chunqiu in December, including beginning of spring, vernal equinox, long summer, summer solstice, beginning of autumn, vernal equinox, beginning of winter and winter solstice. These eight solar terms are the most important of the 24 solar terms. They show the seasonal changes and clearly divide the four seasons of the year. Later, when the book Huai Nan Zi was published, the names of the 24 solar terms were exactly the same as those of the modern ones. This is the earliest record of 24 solar terms in the history of China. With continuous observation, analysis and summary, people find that climate change has certain laws. As long as the production of agriculture and animal husbandry is arranged according to this law, the effect of seeking advantages and avoiding disadvantages can be achieved. As a result, the division of solar terms is gradually enriched, perfected and scientific. Textual research on unearthed cultural relics discovered by archaeology shows that solar terms were adopted in the Western Han Dynasty in China. Eight solar terms and twenty-four solar terms were recorded in Zhou Pian Shu Jing of Han Dynasty. Most of them represent climate change, differences between objects and images, and are closely integrated with agriculture. Therefore, at this time, we can grasp the seasonal changes from the eight solar terms and the twenty-four solar terms and decide to sow and harvest crops in time. By the Qin and Han dynasties more than 2000 years ago, a complete concept of 24 solar terms had been formed.

The formulation of twenty-four solar terms combines the characteristics of astronomy, meteorology and crop growth, so it can accurately reflect the characteristics of natural forces in a year. It can be said that China's ancient working people made a great contribution to the world.