Notes on the date: the explanation of the twenty-eight stars in the old yellow calendar

In western astrology, the zodiac represents different directions of the universe, and people born at different times have different personalities and constellations when they fall in the corresponding directions. And the traditional lunar calendar also has 28 stars.

Astronomers of the ancient Han nationality in China divided the stars visible in the sky into 28 groups, which were called Twenty-eight Nights. One of China's ancient astronomical theories, also known as the Twenty-eight Palace or Twenty-eight Stars, was that ancient China divided the celestial regions near the ecliptic and celestial equator into 28 regions. India, Persia, Arabia and other ancient times also had a saying similar to China's twenty-eight nights.

Twenty-eight constellations, also known as the twenty-eight house or twenty-eight stars, divide the stars in the southern transit into twenty-eight groups, which are a circle of stars distributed along the celestial ecliptic or equator (the equator of the earth extends to the sky). Divided into four groups, also known as four elephants, four beasts, four-dimensional and four-dimensional gods. There are seven stars in each group, and its origin is still not completely clear.

At first, the ancients chose 28 stars to compare the movements of the sun, the moon, gold, wood, water, fire and earth as observation marks. The meaning of "lodge" is similar to the "palace" of the zodiac, which means the constellation table, indicating the position of the sun, the moon and the five stars. In the Tang Dynasty, Twenty-eight Hostels became the main body of the twenty-eight celestial bodies, and these celestial bodies were still named after Twenty-eight Hostels. Different from Sanyuan, as a celestial body, Twenty-eight Hostels are mainly used to divide the ownership of star officials.

Name of 28 hostels:

Seven Nights of the Oriental Black Dragon: Jiao, Kang, Bian, Fang, Xin, Wei and Ji.

Seven nights in North Xuanwu: fighting, cattle, women, air, danger, houses and walls.

Seven nights in the West White Tiger: Kui, Lou, Wei, Chang, Bi, Gou and Shen.

South Suzaku Seven Nights: Well, ghosts, willows, stars, Zhang, wings, birds.

The correspondence between twenty-eight hotels and twelve local branches;

The earthly branch is the core content of ancient astronomy in China and the most important symbol of ancient astronomy in China. The earthly branch originated from the ancient 28 stars, which is another expression of the year. The way to create earthly branches is to use some astrological symbols of 28 stars.