Earthly Branches

The Earthly Branches (Chinese and Japanese: 地支; pinyin: dìzhī; Korean: 지지; or Chinese and Japanese: 十二支; pinyin: shí'èrzhī; Korean: 십이지; literally: "twelve branches") provide one Chinese system for reckoning time.

This system was built from observations of the orbit of Jupiter. Chinese astronomers divided the celestial circle into 12 sections to follow the orbit of 歲星 Suìxīng (Jupiter, the Year Star). Astronomers rounded the orbit of Suixing to 12 years (from 11.86). Suixing was associated with 攝提 Shètí (η Boötis) and sometimes called Sheti.

In correlative thinking, the twelve years of the Jupiter cycle also identify the twelve months of the year, twelve animals (mnemonics for the system), directions, seasons, and Chinese hour in the form of double-hours. When a Branch is used for a double hour, the listed periods are meant. When used for an exact time of a day, it is the center of the period. For instance, 午 (the Horse) means noon or a period from 11am to 1pm. (The jie qi system provided single hours and 15-degree arcs in time and space.)

Chinese seasons are based on observations of the sun and stars. Many Chinese calendrical systems have started the new year on the second new moon after the winter solstice.

The Earthly Branches are today used with the Heavenly Stems in the current version of the "traditional Chinese calendar" and in Taoism. The Ganzhi (Stem-Branch) combination is a fairly new way to mark time; in the second millennium BC, during the Shang era, it was the ten Heavenly Stems that provided the names of the days of the week. The Branches are as old as the Stems (and according to recent archaeology may actually be older), but the Stems were tied to the ritual calendars of Chinese kings. They were not part of the calendrical systems of the majority of Chinese.

The twelve branches

Arctic Side

	Earthly Branch	Chinese		Japanese		Korean (RR)	Mongolian	Manchu	Vietnamese	Chinese zodiac	Japanese zodiac	Direction	Season	Lunar Month	Double Hour
		Mandarin Pinyin	Cantonese Jyutping	on'yomi	kun'yomi
1	子	zǐ	zi2	し(shi)	ね(ne)	자 (ja)	ᠬᠤᠯᠤᠭᠠᠨ᠎ᠠ	ᠰᡳᠩᡤᡝᡵᡳ	tí (SV: tử)	鼠 Rat	鼠	0° (north)	winter	Month 11	11pm to 1am (midnight)
2	丑	chǒu	cau2	ちゅう(chū)	うし(ushi)	축 (chuk) (SK: 추 (chu))	ᠦᠬᠡᠷ	ᡳᡥᠠᠨ	sửu	牛 Ox	牛	30°		Month 12	1am to 3am
3	寅	yín	jan4	いん(in)	とら(tora)	인 (in)	ᠪᠠᠷᠰ	ᡨᠠᠰᡥᠠ	dần	虎 Tiger	虎	60°	spring	Month 1	3am to 5am
4	卯	mǎo	maau5	ぼう(bō)	う(u)	묘 (myo)	ᠲᠠᠤᠯᠠᠢ	ᡤᡡᠯᠮᠠᡥᡡᠨ	mão (non-SV: mẹo)	兔 Rabbit	兎	90° (east)		Month 2	5am to 7am
5	辰	chén	san4	しん(shin)	たつ(tatsu)	진 (jin) (SK: 신 (sin))	ᠯᠤᠤ	ᠮᡠᡩᡠᡵᡳ	thìn (SV: thần)	龙（龍） Dragon	竜	120°		Month 3	7am to 9 am
6	巳	sì	zi6	し(shi)	み(mi)	사 (sa)	ᠮᠣᠭᠠᠢ	ᠮᡝᡳᡥᡝ	tị	蛇 Snake	蛇	150°	summer	Month 4	9am to 11am
7	午	wǔ	ng5	ご(go)	うま(uma)	오 (o)	ᠮᠣᠷᠢ	ᠮᠣᡵᡳᠨ	ngọ	马（馬） Horse	馬	180° (south)		Month 5	11am to 1pm (noon)
8	未	wèi	mei6	び (bi)	ひつじ(hitsuji)	미 (mi)	ᠬᠣᠨᠢ	ᡥᠣᠨᡳᠨ	mùi (SV: vị)	羊 Goat	羊	210°		Month 6	1pm to 3pm
9	申	shēn	san1	しん(shin)	さる(saru)	신 (sin)	ᠪᠡᠴᠢᠨ	ᠪᠣᠨᡳᠣ	thân	猴 Monkey	猿	240°	autumn	Month 7	3pm to 5pm
10	酉	yǒu	jau5	ゆう(yū)	とり(tori)	유 (yu)	ᠲᠠᠬᠢᠶ᠎ᠠ	ᠴᠣᡴᠣ	dậu	鸡（雞） Rooster	鶏	270° (west)		Month 8	5pm to 7pm
11	戌	xū	seot1	じゅつ(jutsu)	いぬ(inu)	술 (sul)	ᠨᠣᠬᠠᠢ	ᡳᠨᡩᠠᡥᡡᠨ	tuất	狗 Dog	犬	300°		Month 9	7pm to 9pm
12	亥	hài	hoi6	がい(gai)	い(i)	해 (hae)	ᠭᠠᠬᠠᠢ	ᡠᠯᡤᡳᠶᠠᠨ	hợi	猪（豬） Pig	猪	330°	winter	Month 10	9pm to 11pm

Some cultures assign different animals: Vietnam replaces the Ox and Rabbit with the water buffalo and cat respectively; Japan replaces the Pig (豚) with the boar (猪); Tibet replaces the Rooster with the bird. In the traditional Kazakh version of the 12-year animal cycle (Kazakh: мүшел, müşel), the Dragon is substituted by a snail (Kazakh: ұлу, ulw), and the Tiger appears as a leopard (Kazakh: барыс, barıs).

Directions

The 24 cardinal directions (ancient Chinese convention places the south (red) at the top).

Even though Chinese has words for the four cardinal directions, Chinese mariners and astronomers/astrologers preferred using the twelve directions of the Earthly Branches, which is somewhat similar to the modern-day practice of English-speaking pilots using o'clock for directions. Since twelve points were not enough for sailing, twelve midpoints were added. Instead of combining two adjacent direction names, they assigned new names as follows:

• For the four diagonal directions, appropriate trigram names of I Ching were used.
• For the rest, the Heavenly Stems were used. According to the Five Elements theory, east is assigned to wood, and the Stems of wood are 甲 (jiǎ) and 乙 (yǐ). Thus they were assigned clockwise to the two adjacent points of the east.

Following is a table of the 24 directions:

	Character	Mandarin name	Korean name	Japanese name	Vietnamese name	Direction
1	子	zǐ	자 (ja)	ne	tí (SV: tử)	0° (north)
2	癸	guǐ	계 (gye) (SK: 규 (gyu))	mizunoto	quý	15°
3	丑	chǒu	축 (chuk) (SK: 추 (chu))	ushi	sửu	30°
4	艮	gèn	간 (gan)	ushitora	cấn	45° (northeast)
5	寅	yín	인 (in)	tora	dần	60°
6	甲	jiǎ	갑 (gap)	kinoe	giáp	75°
7	卯	mǎo	묘 (myo)	u	mão (non-SV: mẹo)	90° (east)
8	乙	yǐ	을 (eul)	kinoto	ất	105°
9	辰	chén	진 (jin) (SK: 신 (sin))	tatsu	thìn (SV: thần)	120°
10	巽	xùn	손 (son)	tatsumi	tốn	135° (southeast)
11	巳	sì	사 (sa)	mi	tị	150°
12	丙	bǐng	병 (byeong)	hinoe	bính	165°
13	午	wǔ	오 (o)	uma	ngọ	180° (south)
14	丁	dīng	정 (jeong)	hinoto	đinh	195°
15	未	wèi	미 (mi)	hitsuji	mùi (SV: vị)	210°
16	坤	kūn	곤 (gon)	hitsujisaru	khôn	225° (southwest)
17	申	shēn	신 (sin)	saru	thân	240°
18	庚	gēng	경 (gyeong)	kanoe	canh	255°
19	酉	yǒu	유 (yu)	tori	dậu	270° (west)
20	辛	xīn	신 (sin)	kanoto	tân	285°
21	戌	xū	술 (sul)	inu	tuất	300°
22	乾	qián	건 (geon)	inui	càn (SV: kiền)	315° (northwest)
23	亥	hài	해 (hae)	i	hợi	330°
24	壬	rén	임 (im)	mizunoe	nhâm	345°

Advanced mariners such as Zheng He used 48-point compasses. An additional midpoint was called by a combination of its two closest basic directions, such as 丙午 (bǐngwǔ) for the direction of 172.5°, the midpoint between 丙 (bǐng), 165°, and 午 (wǔ), 180°.

See also

• Sexagesimal cycle (干支)
• Sheng Xiao
• Celestial stem
• Chinese calendar
• (A study of the cardinal directions chart)

External links

• Heavenly Stems and Earthly Branches - Hong Kong Observatory