Celestial stem

The ten Celestial or Heavenly Stems (Chinese: 天干; pinyin: tiāngān) are a Chinese system of ordinals that first appear during the Shang dynasty, ca. 1250 BC, as the names of the ten days of the week. They were also used in Shang-period ritual as names for dead family members, who were offered sacrifices on the corresponding day of the Shang week. The Heavenly Stems were used in combination with the Earthly Branches, a similar cycle of twelve days, to produce a compound cycle of sixty days. Subsequently, the Heavenly Stems lost their original function as names for days of the week and dead kin, and acquired many other uses, the most prominent and long lasting of which was their use together with the Earthly Branches as a 60-year calendrical cycle.

Table

	Celestial Stem	Chinese			Japanese		Korean (RR)	Manchu (Möllendorff)	Vietnamese	Yin and Yang (陰陽)	Wu Xing (五行)	Wu Xing correlations
		Mandarin Pinyin	Wu Wuupin	Cantonese Jyutping	on'yomi	kun'yomi
1	甲	jiǎ	ciaeh43	gaap3	kō	kinoe	갑 (gap)	ᠨᡳᠣᠸᠠᠩᡤᡳᠶᠠᠨ (niowanggiyan)	giáp	陽 (yang)	木 (wood)	東 East
2	乙	yǐ	ieh43	jyut6	otsu	kinoto	을 (eul)	ᠨᡳᠣᡥᠣᠨ (niohon)	ất	陰 (yin)
3	丙	bǐng	pin51	bing2	hei	hinoe	병 (byeong)	ᡶᡠᠯᡤᡳᠶᠠᠨ (fulgiyan)	bính	陽 (yang)	火 (fire)	南 South
4	丁	dīng	ting44	ding1	tei	hinoto	정 (jeong)	ᡶᡠᠯᠠᡥᡡᠨ (fulahūn)	đinh	陰 (yin)
5	戊	wù	vu231	mou6	bo	tsuchinoe	무 (mu)	ᠰᡠᠸᠠᠶᠠᠨ (suwayan)	mậu	陽 (yang)	土 (earth)	中 Middle
6	己	jǐ	ci51	gei2	ki	tsuchinoto	기 (gi)	ᠰᠣᡥᠣᠨ (sohon)	kỷ	陰 (yin)
7	庚	gēng	keng44	gang1	kō	kanoe	경 (gyeong)	ᡧᠠᠨᠶᠠᠨ (šanyan)	canh	陽 (yang)	金 (metal)	西 West
8	辛	xīn	sin44	san1	shin	kanoto	신 (sin)	ᡧᠠᡥᡡᠨ (šahūn)	tân	陰 (yin)
9	壬	rén	nyin223	jam4	jin	mizunoe	임 (im)	ᠰᠠᡥᠠᠯᡳᠶᠠᠨ (sahaliyan)	nhâm	陽 (yang)	水 (water)	北 North
10	癸	guǐ	kue51	gwai3	ki	mizunoto	계 (gye)	ᠰᠠᡥᠠᡥᡡᠨ (sahahūn)	quý	陰 (yin)

Origin

The Shang people believed that there were ten suns, each of which appeared in order in a ten-day cycle (旬; xún). The Heavenly Stems (tiāngān 天干) were the names of the ten suns, which may have designated world ages as did the Five Suns and the Six Ages of the World of Saint Augustine. They were found in the given names of the kings of the Shang in their Temple Names. These consisted of a relational term (Father, Mother, Grandfather, Grandmother) to which was added one of the ten gān names (e.g. Grandfather Jia). These names are often found on Shang bronzes designating whom the bronze was honoring (and on which day of the week their rites would have been performed, that day matching the day designated by their name). David Keightley, a leading scholar of ancient China and its bronzes, believes that the gān names were chosen posthumously through divination. Some historians think the ruling class of the Shang had ten clans, but it is not clear whether their society reflected the myth or vice versa. The associations with Yin-Yang and the Five Elements developed later, after the collapse of the Shang Dynasty.

The literal meaning of the characters was roughly as follows:

Celestial Stem	Meaning
	Original	Modern
甲	shell	first (book I, person A etc.), helmet, armor, words related to beetles, crustaceans, methyl group, fingernails, toenails
乙	fishguts	second (book II, person B etc.), twist, words related to the ethyl group
丙	fishtail	third, bright, fire, fishtail (rare)
丁	nail	fourth, male adult, robust, T-shaped, to strike, a surname
戊	lance	(not used)
己	threads on a loom	self
庚	evening star	age (of person)
辛	to offend superiors	bitter, piquant, toilsome
壬	burden	to shoulder, to trust with office
癸	disposed grass	(not used)

Current usage

The Stems are still commonly used nowadays in Chinese counting systems similar to the way the alphabet is used in English. For example:

• Names in legal documents and contracts where English speakers would use A, B, C, etc. Korea and Japan also use heavenly stems on legal documents in this way. In Korea, letters gap (甲) and eul (乙) are consistently used to denote the larger and the smaller contractor (respectively) in a legal contract, and are sometimes used as synonyms for such; this usage is also common in the Korean IT industry.
• Choices on multiple choice exams, surveys, etc.
• Organic chemicals (e.g. methanol: 甲醇 jiǎchún; ethanol: 乙醇 yǐchún). See Organic nomenclature in Chinese.
• Diseases (Hepatitis A: 甲型肝炎 jiǎxíng gānyán; Hepatitis B: 乙型肝炎 yǐxíng gānyán)
• Sports leagues (Serie A: 意甲 yìjiǎ)
• Vitamins (although currently, in this case, the ABC system is more popular)
• Characters conversing in a short text (甲 speaks first, 乙 answers)
• Students' grades in Taiwan: with an additional Yōu (優 "Excellence") before the first celestial stem Jiǎ. Hence, American grades A, B, C, D and F correspond to 優, 甲, 乙, 丙 and 丁 (yōu, jiǎ, yǐ, bǐng, dīng).

• In astrology and Feng Shui. The Celestial Stems and Earth Branches form the four pillars of Chinese metaphysics in Qi Men Dun Jia and Da Liu Ren.

See also

• Sexagenary cycle
• Earthly Branches
• Chinese numerals
• Organic nomenclature in Chinese

External links

• Heavenly Stems and Earthly Branches - Hong Kong Observatory

• Smith (2011).
• David N. Keightley, "The Quest for Eternity in Ancient China: The Dead, Their Gifts, Their Names" in Ancient Mortuary Traditions of China ed. by George Kuwayama. Los Angeles County Museum of Art, 1987, pp. 12–24.
• William McNaughton. Reading and Writing Chinese. Tokyo: Charles E. Tuttle, 1979.
• Wenlin Dictionary: Picture of a fish tail.
• Wenlin Dictionary: 己 may have depicted thread on a loom; an ancient meaning was 'unravel threads', which was later written 紀 jì. 己 was borrowed both for the word jǐ 'self', and for the name of the sixth Heavenly Stem (天干).
• Wenlin Dictionary: "The seal has 𢆉 'knock against, offend' below, and 亠 above; the scholastic commentators say: to offend (亠 = ) 上 the superiors"
• Wenlin Dictionary: 壬 rén depicts "a 丨 carrying pole supported 一 in the middle part and having one object attached at each end, as always done in China" --Karlgren(1923). (See 扁担 biǎndan). Now the character 任 rèn has the meaning of carrying a burden, and the original character 壬 is used only for the ninth of the ten heavenly stems (天干).
• Wenlin Dictionary: 癶 "stretch out the legs" + 天; The nicely disposed grass, on which the Ancients poured the libations offered to the Manes