Solar terms and legislation

The twenty-four solar terms we are using now are actually the combination of the twenty-four solar terms in ancient China and the western solar calendar. More than 400 years ago, China's calendar, which had been used for hundreds of years, was in disrepair, and the error was getting bigger and bigger. Later, under the leadership of foreign missionary Tang Ruowang and others, the twenty-four solar terms were revised according to the Gregorian calendar (mainly the time when the solar terms were revised), which has been in use ever since.

Our country not only uses the solar calendar, but also inherits the lunar calendar. Many traditional festivals are based on the lunar calendar. In ancient times, the calendar was related to a country's agricultural production, and its importance was self-evident.

The Gregorian calendar we use belongs to the Gregorian calendar, which is based on the law of the earth's revolution around the sun. For example, the period of revolution of the Earth is 365.2422 days, so a year in the Gregorian calendar is 365 days, and the extra error is made up by leap years, so there are provisions for ordinary leap years and century leap years.

If the calendar is made according to the moon's revolution around the earth, it is called lunar calendar, and the period of the moon's phase change is 29.53 days, and the period of the moon's revolution is 27.32 days; The lunar calendar we use has the characteristics of both the solar calendar and the lunar calendar, so the lunar calendar is essentially a yin-yang calendar. Although there are both advantages, it is more complicated to use.

There are 24 solar terms in the lunar calendar. As early as Shang Dynasty, the ancients had four solar terms: midsummer, midsummer, midsummer and midsummer. Later, the ancients added more solar terms according to the law of seasonal changes. By the Qin and Han dynasties, the 24 solar terms were basically finalized.

For example, in BC 104, taichu calendar first included 24 solar terms in the calendar, and set the year of return as 365.2502 days, and the first month of the lunar calendar as 29.530 days. Taichu calendar method was used in 188, and the calendar was revised countless times later.

Therefore, it can be affirmed that the 24 solar terms are the product of China's ancient farming civilization and the crystallization of ancient wisdom, and were listed in UNESCO's Representative List of Intangible Cultural Heritage of Humanity in 20 16.

According to the names of solar terms, we can know the changes of seasons or the planting of crops. For example, we know that when we plant food, we know that it will enter deep winter when it is cold.

During the Chongzhen period (about1mid-7th century), the calendar used in the Qing Dynasty was in disrepair and showed great deviation, so the state ordered the calendar to be rebuilt, and under the leadership of Tang Ruowang, a foreign missionary, and Xu Guangqi, a famous scientist in ancient China, the Chongzhen almanac was formulated.

The Chongzhen almanac comprehensively introduced the knowledge of European astronomy, and revised the China calendar with reference to the western Gregorian calendar, such as the revision of the 24 solar terms, which greatly increased the accuracy of the lunar calendar and has been used ever since.

The change of seasons is caused by the revolution of the earth around the sun. We turned the earth around 15? As a solar term, the 24 solar terms are basically evenly distributed in the Gregorian calendar, reflecting the changes of the four seasons; Because the earth revolves around the sun in an elliptical orbit, the interval of days between every two adjacent solar terms is not necessarily equal.

In essence, the formulation of the twenty-four solar terms is based on the solar calendar, and the Gregorian calendar belongs to the Gregorian calendar, so the twenty-four solar terms can coincide with the Gregorian calendar; For example, Tomb-Sweeping Day is always around April 5th (4th, 5th and 6th) of the Gregorian calendar, and the winter solstice is always around February 22nd of the Gregorian calendar, but the dates of the lunar calendar don't match every year.