Why is the second day of the second lunar month silver moon instead of Uzuki? When did the Chinese zodiac start to change?

There are 24 solar terms every year, and the lunar month is bounded by solar terms, that is, 12 solar terms.

There is a saying of "three corrections" or "three constructions" in the ancient calendar of China. In the Xia, Yin and Zhou dynasties, which month of the year was designated as the "first month" (referring to the first month in the Han calendar, which is different from the official calendar) was different. The Zhou Dynasty was 1 1 month (called "simplified characters"), the Yin Dynasty was1February (called "simplified ugliness"), and the Xia Dynasty was. "Sword" refers to the place where the top of "Big Dipper" and "bucket handle" point. Seen from the earth, the running law of the Big Dipper is different from that of the moon in terms of time.

The interpretation of the image is: If the space around the Big Dipper is compared to a large dial, we can use 1, 2,3 to scale its hours? Compare them to "Zi", "Ugly", "Yin" and "Mao" respectively? 12 hour and North, Northeast, Northeast and East? 12 square.

Taking the spoon-shaped Big Dipper (as the saying goes, "one spoon in the Big Dipper") as the "hour hand" and the "bucket head" (that is, the first four stars) as the center, and rotating clockwise from the northeast (cloudy direction), there will be "Jianmao", "Chen Jian" and "Jianji" in turn. "Jian Hai" and other celestial phenomena, according to the inherent law of celestial movement, every time bucket handle rotates (or an azimuth), it means that time has passed (or can be distinguished as pointing to the northeast); When the "hour hand" moves for a whole week, it means that the time has just passed one year (of course, there is also a "leap surplus" in the middle, I will briefly talk about it). Finally, he returned to Yin Jian, so bucket handle returned to Yin.

The first month is the first month of the year. Before the Qin Dynasty, people called themselves Zheng Zheng in the Six Kingdoms period. After Qin Shihuang unified the six countries, he called himself Zheng Zheng. However, his name is Ying Zheng. Qin Shihuang ordered that only he could call me Zheng, and everyone else thought it was not possible. Speaking of China New Year, people say that Zheng Zhengyue has arrived. After hearing this, Qin Shihuang was furious and changed the fourth tone of the first month to one.