Notes on the date: the explanation of the twenty-eight stars in the 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. There are also 28 stars in the traditional lunar calendar.

Astronomers of the ancient Han nationality in China divided the stars visible in the sky into 28 groups, which were called Twenty-eight Hostels. 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 the twenty-eight stars, divide the stars in the southern transit into twenty-eight groups, which are a circle of stars distributed along the ecliptic or equator of the celestial sphere (the equator of the earth extends to the sky). It is 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 the earth as observation marks. The meaning of "lodge" is similar to the "palace" of the zodiac, which means the constellation table, indicating the positions of the sun, the moon and the five stars. In the Tang Dynasty, Twenty-eight Hostels became the main body of twenty-eight celestial domains, and these celestial domains were still named after Twenty-eight Hostels. Unlike Sanyuan, as a celestial region, 28 hotels 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 Xuanwu: fighting, cows, women, emptiness, danger, rooms and walls.

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

Seven Nights of South Suzaku: Well, Ghost, Willow, Star, Zhang, Wing and Bird.

Communication between twenty-eight hotels and twelve branches;

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