Sexagenary Cycle: Ten Heavenly Stems and Twelve Earthly Branches

Sexagenary Cycle: Ten Heavenly Stems and Twelve Earthly Branches

Source: Wikipedia

The Chinese sexagenary cycle, also known as Stems-Branches, is a cyclic numeral system of 60 combinations of the two basic cycles, the ten Heavenly Stems and the twelve Earthly Branches

This traditional Chinese calendrical system is used as a means of numbering days and years, not only in China but also in other East Asian nations like Japan, Korea, and Vietnam. The Sexagenary system is also important in Chinese astrology and Chinese fortune telling.

The cycle was used in China since the second millennium BC (it has been found on Shang dynasty oracle bones), as a means of naming days (just as western cultures use the days in the week). This use of the cycle for days is attested throughout the Zhou dynasty. For instance, most entries in the Spring and Autumn Annals use this system. Its use for recording years is more recent. It became widespread in the Western Han Dynasty (202 BC- 8 AD), and might have begun in the late Warring States period. The year 1984 began the present cycle, and 2044 will begin another.

The calendar is calculated by combining the Ten Heavenly Stems and the Twelve Earthly Branches. These two sets of terms were used to enumerate years of the civil calendar. Combining the series form a greater cycle of 60 terms, as the least common multiple of 10 and 12 is 60. The first term is formed by adding the first stem to the first branch, then the second stem to the second branch, and so on. If you start with kinoe-ne/kōshi, so the 61st year would also be kinoe-ne. This was how the tradition of celebrating the 60th birthday began. This counting system employing things of nature and animals create many myths, and people of Japan today still consider the good and bad luck of certain days and years.

The 1st day of a new year in the sexagenary cycle should be the Lichun.

The Tibetan calendar also counts years using a 60-year cycle based on 12 animals and 5 elements, but while the first year of the Chinese cycle is always the year of the Wood Rat, the first year of the Tibetan cycle is the year of the Fire Hare (year #4 on the Chinese cycle).

1. Ten Heavenly Stems

	Heavenly Stem	Chinese name (Mandarin pron. in pinyin)	Yin yang	Wu xing
1	甲	jiǎ	yang	wood
2	乙	yǐ	yin
3	丙	bǐng	yang	fire
4	丁	dīng	yin
5	戊	wù	yang	earth
6	己	jǐ	yin
7	庚	gēng	yang	metal
8	辛	xīn	yin
9	壬	rén	yang	water
10	癸	guǐ	yin

2. Twelve Earthly Branches

	Earthly Branch	Chinese name (Mandarin pron. in pinyin)	Chinese zodiac	Corresponding hours
1	子	zǐ	Rat	11 p.m. to 1 a.m.
2	丑	chǒu	Ox/Buffalo	1 to 3 a.m.
3	寅	yín	Tiger	3 to 5 a.m.
4	卯	mǎo	Rabbit/Hare	5 to 7 a.m.
5	辰	chén	Dragon	7 to 9 a.m.
6	巳	sì	Snake	9 to 11 a.m.
7	午	wǔ	Horse	11 a.m. to 1 p.m.
8	未	wèi	Sheep/Goat	1 to 3 p.m.
9	申	shēn	Monkey	3 to 5 p.m.
10	酉	yǒu	Chicken/Rooster	5 to 7 p.m.
11	戌	xū	Dog	7 to 9 p.m.
12	亥	hài	Pig/Boar	9 to 11 p.m.

*The names of several animals can be translated into English in several different ways.

3. Sexagenary Cycle

	Stem-Branch	Chinese name	Associations
1	甲子	jiǎ-zǐ	Yang Wood Rat
2	乙丑	yǐ-chǒu	Yin Wood Ox
3	丙寅	bǐng-yín	Yang Fire Tiger
4	丁卯	dīng-mǎo	Yin Fire Rabbit
5	戊辰	wù-chén	Yang Earth Dragon
6	己巳	jǐ-sì	Yin Earth Snake
7	庚午	gēng-wǔ	Yang Metal Horse
8	辛未	xīn-wèi	Yin Metal Sheep
9	壬申	rén-shēn	Yang Water Monkey
10	癸酉	guǐ-yǒu	Yin Water Chicken
11	甲戌	jiǎ-xū	Yang Wood Dog
12	乙亥	yǐ-hài	Yin Wood Pig
13	丙子	bǐng-zǐ	Yang Fire Rat
14	丁丑	dīng-chǒu	Yin Fire Ox
15	戊寅	wù-yín	Yang Earth Tiger
16	己卯	jǐ-mǎo	Yin Earth Rabbit
17	庚辰	gēng-chén	Yang Metal Dragon
18	辛巳	xīn-sì	Yin Metal Snake
19	壬午	rén-wǔ	Yang Water Horse
20	癸未	guǐ-wèi	Yin Water Sheep
21	甲申	jiǎ-shēn	Yang Wood Monkey
22	乙酉	yǐ-yǒu	Yin Wood Chicken
23	丙戌	bǐng-xū	Yang Fire Dog
24	丁亥	dīng-hài	Yin Fire Pig
25	戊子	wù-zǐ	Yang Earth Rat
26	己丑	jǐ-chǒu	Yin Earth Ox
27	庚寅	gēng-yín	Yang Metal Tiger
28	辛卯	xīn-mǎo	Yin Metal Rabbit
29	壬辰	rén-chén	Yang Water Dragon
30	癸巳	guǐ-sì	Yin Water Snake
31	甲午	jiǎ-wǔ	Yang Wood Horse
32	乙未	yǐ-wèi	Yin Wood Sheep
33	丙申	bǐng-shēn	Yang Fire Monkey
34	丁酉	dīng-yǒu	Yin Fire Chicken
35	戊戌	wù-xū	Yang Earth Dog
36	己亥	jǐ-hài	Yin Earth Pig
37	庚子	gēng-zǐ	Yang Metal Rat
38	辛丑	xīn-chǒu	Yin Metal Ox
39	壬寅	rén-yín	Yang Water Tiger
40	癸卯	guǐ-mǎo	Yin Water Rabbit
41	甲辰	jiǎ-chén	Yang Wood Dragon
42	乙巳	yǐ-sì	Yin Wood Snake
43	丙午	bǐng-wǔ	Yang Fire Horse
44	丁未	dīng-wèi	Yin Fire Sheep
45	戊申	wù-shēn	Yang Earth Monkey
46	己酉	jǐ-yǒu	Yin Earth Chicken
47	庚戌	gēng-xū	Yang Metal Dog
48	辛亥	xīn-hài	Yin Metal Pig
49	壬子	rén-zǐ	Yang Water Rat
50	癸丑	guǐ-chǒu	Yin Water Ox
51	甲寅	jiǎ-yín	Yang Wood Tiger
52	乙卯	yǐ-mǎo	Yin Wood Rabbit
53	丙辰	bǐng-chén	Yang Fire Dragon
54	丁巳	dīng-sì	Yin Fire Snake
55	戊午	wù-wǔ	Yang Earth Horse
56	己未	jǐ-wèi	Yin Earth Sheep
57	庚申	gēng-shēn	Yang Metal Monkey
58	辛酉	xīn-yǒu	Yin Metal Chicken
59	壬戌	rén-xū	Yang Water Dog
60	癸亥	guǐ-hài	Yin Water Pig

The sexagenary cycle was first used for days in the Shang Dynasty, and later also used for years and less commonly for months.

For example, the year 2000 was the 17th year of the 78th sexagenary cycle, a gēng-chén year (庚辰年), a year of the Yang Metal Dragon. Therefore, 2006 is the 23rd year of the 78th sexagenary cycle, called a bǐng-xū year (丙戌年), a year of the Yang Fire Dog; 2007 a year of the Yin Fire Pig.

The naming of the months and days is not common now, although they are shown on Chinese calendars and almanacs.

• Attention: In common practice, the “combination” elements (Chinese agricultural calendar) should be applied for the Sexagenary Cycle. Either the “Heavenly Stem” or the “Earthly
• Branch” alone is not enough to determine the element for any year within the 60 years of the Sexagenary Cycle.
• The writing of “Yang Earth Rat”(e.g., 2008), etc., is not recommended for use, because people might misinterpret “Earth” as the “Element” of that year (2008).