What does fear come from?
It was once called "Qi Zhe" in history, and Xia Zhengxiao compiled by the Western Han Dynasty said: "Qi Zhe in the first month". It is said that the sixth generation emperor of the Han Dynasty, Emperor Jing of the Han Dynasty, taboo "Qi", in order to avoid it, changed "Qi" into "Jing" with similar meaning.
After the Tang Dynasty, it was no longer necessary to avoid the word "Qi" and began to use the name "Qi Zhe". However, due to various reasons, Da Liyan once again used the word "elite", which is still in use today. Like China, Japan used "Jingzhe" in the calendars of past dynasties. Since then, Japan has also adopted Dayan calendar and Xuanming calendar.
During the period of Emperor Wu of the Western Han Dynasty, "Twenty-four solar terms" were included in taichu calendar as a supplement to guide the agricultural calendar. In the middle and lower reaches of the Yellow River, the day with the longest sun shadow and the shortest day is taken as the winter solstice, and the winter solstice is taken as the starting point of the "24 solar terms", and the winter solstice and the next winter solstice are divided into 24 equal parts.
The time between solar terms is equal, and the interval between solar terms is 15 days, so it is also called "average time method". The solar term determined by the "average time method" is 75 days from winter to the future.
In China, the time when the spring thunder begins to ring is different from morning till night. On the average for many years, thunder can be heard in southern Yunnan around the end of 1, while the first thunder day in Beijing is in late April. The saying that "thunder begins with you" is consistent with the climate law in Jiangnan.