28 Hsiu

In China the mansions of the moon were called Hsiu. There are 28 Hsiu, i.e. 7 for each Guardian of the night sky x 4 = 28. Note that the Days of the Week (q.v.) begin with Thursday.

The 28 Mansions + the 3 Enclosures make the 31 Regions.

Qinlong Green Dragon Eastern Quarter of the Sky

Jiao Horn Thursday
Kang Neck Friday
Di Base Saturday
Fang House Sunday
Xin Heart Monday
Wei Tail Tuesday
Ji Winnowing Basket Wednesday
Jiao, Kang, Di, Fang, Xin, Wei, Ji

Xuanwu Black Warrior Northern Quarter of the Sky
Dou Southern Dipper Thursday
Niu Ox-boy Friday
Nu Weaving girl Saturday
Xu Void Sunday
Wei Danger Monday
Shi Room Tuesday
Bi Wall Wednesday
Dou, Niu, Nu, Xu Wei, Shi, Bi

Baihu White Tiger Western Quarter of the Sky
Kui Astride Thursday
Lou Tether Friday
Wei Stomach Saturday
Mao Pleiades Sunday
Bi Net Monday
Zi Beak Tuesday
San Orion Wednesday
Kui, Lou, Wei, Mao, Bi, Zi, San

Zhuque Zhuniao Red Rice Sparrow or Red Bird Southern Quarter
of the Sky

Jing Well Thursday
Gui Ghost Friday
Liu Willow Saturday
Xing Stars Sunday
Zhang Bow Monday
Yi Wings Tuesday
Zhen Chariot Wednesday
Jing, Gui, Liu, Xing, Zhang, Yi, Zhen

Tang Dynasty Mirror shows cycles in Chinese calendar. Innermost circle shows 4 cosmological animals depicting the 4 cardinal points N,S,E,W and the 4 seasons. Next ring shows 12 animals signifying the 12 year Jupiter cycle. Outer ring has 28 creatures representing the 28 Chinese ‘hsiu’ or stellar station.