Are the 24 solar terms in ancient times still accurate? Will there be deviations after thousands of years?

The twenty-four solar terms are divided according to the position of the sun on the ecliptic (that is, the orbit of the earth around the sun). Depending on the sun starting from the vernal equinox (longitude zero, at this moment the sun shines vertically on the equator), every advance of 15 degrees is a solar term; After a week's operation, I returned to the vernal equinox, which is a tropical year with 360 degrees, so it is divided into 24 solar terms. The dates of solar terms are relatively fixed in the solar calendar. For example, beginning of spring in the solar calendar always falls between February 3rd and 5th. However, in the lunar calendar, the date of solar terms is not easy to determine. Take beginning of spring as an example. It can be the first day of the lunar calendar in the previous year, 65438+February 15, and the latest is the first month, 15. The current lunar calendar is neither a lunar calendar nor a solar calendar, but a combination of lunar and solar calendars. There is a leap month in the lunar calendar. If one year is counted from the first day of the first month to the New Year's Eve of the twelfth month, the number of days in the lunar calendar varies greatly (leap year is 13 months). In order to standardize the number of years, the first day of the Lunar New Year (heavenly stems and earthly branches) is not the first day of the first month, but beginning of spring. In other words, a year in the lunar calendar is the day before from beginning of spring in that year to beginning of spring in the following year. For example, 2008 is the fifth year of the lunar calendar. The first day of Wuzi began not on February 7, 2008 (the first day of the first lunar month), but on February 4, 2008 in Gregorian calendar.

"There are no rules for farming, and it all depends on solar terms. This proverb has been widely circulated among the people in China since ancient times, and it has not changed so far. It can be seen that solar terms are valued by ordinary farmers. Twenty-four solar terms were originally created by ancient calendar jurists in China, and they were used to express the climate change cycle of 1 year, so as to make up for the shortcomings that the lunar calendar date could not cope with seasonal changes in the past. Ancient farmers learned from long-term life experience that agriculture is closely related to seasons. Therefore, as long as they look at what solar terms they were in at that time, they can understand the climate state of this period and carry out farming in time to avoid the disconnection between climate products and seasonal changes and affect the harvest. Therefore, for people in agricultural society, solar terms are closely related to farming such as spring ploughing, summer harvest, autumn harvest and winter storage, and are also indispensable guidelines in daily life.

So there will be no deviation.