Heavenly Stems and Earthly Branches, the crash course

The sixty Jia Zi

There are ten stems and twelve branches. They pair up and step forward together: Jia Zi, Yi Chou, Bing Yin and so on. The lowest common multiple of ten and twelve is sixty, so it takes sixty pairs to get back to Jia Zi, which is why the cycle is called the "sixty Jia Zi". Years, months, days and hours are all counted this way, so anyone's birth can be written as eight characters, called the Four Pillars.

The pairing follows a pattern: yang stems only pair with yang branches, and yin stems with yin branches. Jia, Bing, Wu, Geng and Ren are yang stems; Zi, Yin, Chen, Wu, Shen and Xu are yang branches. So there is a Jia Zi but no Jia Chou, which is also why there are exactly sixty pairs rather than a hundred and twenty.

When does the Zi Wei year change?

In Zi Wei Dou Shu the year changes on the first day of the first lunar month. Ba Zi usually changes the year at Li Chun, the start of spring, and the two often disagree for people born in late January or early February: Li Chun has passed but Lunar New Year hasn't, so Ba Zi already counts the new year while Zi Wei still counts the old one. Xingge follows most Zi Wei chart software and uses Lunar New Year. If you compare against a Ba Zi year pillar and they don't match, this is usually why.

What the stems do in Zi Wei

• The stem of your birth year sets your birth-year transformations. Someone born in a Jia year, for example, has Lian Zhen Hua Lu, Po Jun Hua Quan, Wu Qu Hua Ke and Tai Yang Hua Ji.
• Each cell's palace stem: the twelve cells each get a stem too. It sets the Five Elements Bureau and is used for Flying Stars and self-transformation.
• The stems of Decade and Annual Luck set the transformations for those periods.
• Yin and yang: for men born in a yang-stem year and women born in a yin-stem year, the Decade Luck moves clockwise; otherwise it moves counterclockwise. This is called yin-yang male and female, and Chapter 6 uses it.

How the palace stems are set

The "Qi Wu Xing Yin Li" in volume two of the *Quan Shu*:

In Jia and Ji years, start at Bing Yin; in Yi and Geng years, start at Wu Yin; in Bing and Xin years, start at Geng Yin; in Ding and Ren years, start at Ren Yin; in Wu and Gui years, start at Jia Yin.

That is: look at the stem of your birth year, use it to set the stem of the Yin cell, then continue the stems clockwise in order. For a Jia year, for example, Yin is Bing Yin, Mao is Ding Mao, and so on round to Chou. Ba Zi uses the same rhyme, called the "Five Tigers". Because there are only ten stems, by the end the stems of the Zi and Chou cells repeat those of Yin and Mao.

Na Yin: where the Five Elements Bureau comes from

Every stem-branch pair has a "Na Yin element". The *Quan Shu* includes the "Na Yin Song of the Sixty Jia Zi", which begins "Jia Zi and Yi Chou, metal in the sea; Bing Yin and Ding Mao, fire in the furnace": two pairs per line, thirty lines for all sixty. Look up the stem-branch pair of your Life Palace in this song and you get your Five Elements Bureau.

The Na Yin element is not the same as the element of the stem or branch itself. Jia is wood and Zi is water, yet the Na Yin of Jia Zi is metal. So don't guess the bureau from the element of the stem or branch; look it up.

What the branches do in Zi Wei

• Seats: the twelve branches are the twelve cells of the chart, with Yin at the bottom left.
• Opposite palace: two cells six apart face each other, like Zi and Wu, or Mao and You.
• Trine: three cells four apart form a triangle: Shen-Zi-Chen, Yin-Wu-Xu, Si-You-Chou and Hai-Mao-Wei. The San Fang Si Zheng is a trine plus the opposite palace.
• The branch of your birth year: many stars are placed by it, such as Tian Ma and Hong Luan, and the Body Master is also set by it.

The Five Elements

Wood feeds fire, fire makes earth, earth bears metal, metal carries water, and water nourishes wood: this is the generating cycle. Wood restrains earth, earth restrains water, water restrains fire, fire restrains metal, and metal restrains wood: this is the restraining cycle. Unlike Ba Zi, Zi Wei doesn't put the elements center stage. They mostly come up in the Five Elements Bureau and in the elements of the stars, for example the *Quan Shu* assigns Wu Qu to metal and Tai Yin to water. Knowing which way the two cycles run is enough.