Chinese calendars

Before it officially adopted the Gregorian calendar in 1912, China had two calendars, one lunisolar and one solar.

The Chinese lunisolar calendar

The civil calendar, used in official records since at least the 10th century bce, was lunisolar, and consisted of 12 months each of 29 or 30 days. Each month began on a new moon. To make up the difference between 12 lunations (of about 29½ days each) and the (about) 365¼ day solar year, an extra month (runyue) was added 22 times in every 60-year cycle (the 60 year cycle is explained below). The various early calendars differed mainly in the day on which the year began. By 104 bce it had been settled that the year begins on the second new moon after the winter solstice (it always falls between January 21 and February 20 in the Gregorian calendar.)

Various rules determine when an intercalary month may be added and their application, like every other aspect of the calendar, was a prerogative of the court.

The intercalary month cannot be added after the first, eleventh, or twelfth month.

The spring equinox must occur in the second month, the autumnal equinox in the eighth, and the winter solstice in the eleventh.

Names of the years: the 60 year cycle

Each year is given a name using a system which is at least 2,000 years old. Two series, one with ten items and one with twelve. Each year is assigned a character from each list, in order. In 60 years (60 is the least common multiple of 10 and 12), simultaneously back at the beginning of both lists.

the Ten Celestial Stems,
shi tiangan
		associated with
1	jia	wood
2	yi	wood
3	bing	fire
4	ding	fire
5	wu	earth
6	ji	earth
7	geng	metal
8	xin	metal
9	ren	water
10	gui	water

the Twelve Hourly Branches,
shier dizhi
		Japan	corresponding animal, shengxiao
1	zi	ne	shu, rat
2	chou	ushi	niu, ox
3	yin	tora	hu, tiger
4	mao	u	tu, hare
5	chen	tatsu	long, dragon
6	si	mi	she, snake
7	wu	uma	ma, horse
8	wei	hitsuji	yang, sheep
9	shen	saru	hou, monkey
10	you	tori	ji, cock
11	xu	inu	quan, dog
12	hai	i	zhu, pig

60-Year Cycle, Ganzhi
Number in cycle	Name of year	Celestial Stem	Hourly Branch	Western Years*
1	jiazi	jia	zi	1924, 1984
2	yichou	yi	chou	1925, 1985
3	bingyin	bing	yin	1926, 1986
4	dingmao	ding	mao	1927, 1987
5	wuchen	wu	chen	1928, 1988
6	jisi	ji	si	1929, 1989
7	gengwu	geng	wu	1930, 1990
8	xinwei	xin	wei	1931, 1991
9	renshen	ren	shen	1932, 1992
10	guiyou	gui	you	1933, 1993
11	jiaxu	jia	xu	1934, 1994
12	yihai	yi	hai	1935, 1995
13	bingzi	bing	zi	1936, 1996
14	dingchou	ding	chou	1937, 1997
15	wuyin	wu	yin	1938, 1998
16	jimao	ji	mao	1939, 1999
17	gengchen	geng	chen	1940, 2000
18	xinsi	xin	si	1941, 2001
19	renwu	ren	wu	1942, 2002
20	guiwei	gui	wei	1943, 2003
21	jiashen	jia	shen	1944, 2004
22	yiyou	yi	you	1945, 2005
23	bingxu	bing	xu	1946, 2006
24	dinghai	ding	hai	1947, 2007
25	wuzi	wu	zi	1948, 2008
26	jichou	ji	chou	1949, 2009
27	gengyin	geng	yin	1950, 2010
28	xinmao	xin	mao	1951, 2011
29	renchen	ren	chen	1952, 2012
30	guisi	gui	si	1953, 2013
31	jiawu	jia	wu	1954, 2014
32	yiwei	yi	wei	1955, 2015
33	bingshen	bing	shen	1956, 2016
34	dingyou	ding	you	1957, 2017
35	wuxu	wu	xu	1958, 2018
36	jihai	ji	hai	1959, 2019
37	gengzi	geng	zi	1960, 2020
38	xinchou	xin	chou	1961, 2021
39	renyin	ren	yin	1962. 2022
40	guimao	gui	mao	1963, 2023
41	jiachen	jia	chen	1964, 2024
42	yisi	yi	si	1965, 2025
43	bingwu	bing	wu	1966, 2026
44	dingwei	ding	wei	1967, 2027
45	wushen	wu	shen	1968, 2028
46	jiyou	ji	you	1969, 2029
47	gengxu	geng	xu	1970, 2030
48	xinhai	xin	hai	1971, 2031
49	renzi	ren	zi	1972, 2032
50	guichou	gui	chou	1973, 2033
51	jiayin	jia	yin	1974, 2034
52	yimao	yi	mao	1975, 2035
53	bingchen	bing	chen	1976, 2036
54	dingsi	ding	si	1977, 2037
55	wuwu	wu	wu	1978, 2038
56	jiwei	ji	wei	1979, 2039
57	gengshen	geng	shen	1980, 2040
58	xinyou	xin	you	1981, 2041
59	renxu	ren	xu	1982, 2042
60	guihai	gui	hai	1983, 2043

*Remember that the Chinese year begins and ends later than the Gregorian year does. Someone born in January before the 21st was definitely born in the preceding Chinese year.

Divisions of the year

In addition to the months, already mentioned, and four seasons based on the solstices and equinoxes, the year was also divided into 24 periods of 15 days, called qi. The qi at the beginnings and ends of seasons, shown in green, were known as bajie.

The 24 Qi
	Jieqi	Translation	In Gregorian calendar, begins on
1	Dongzhi	Winter solstice	22 or 23 Dec.
2	Xiaohan	Slight cold	6 or 7 Jan.
3	Dahan	Great cold	21 or 22 Jan.
4	Lichun	Start of spring	4 or 5 Feb.
5	Yushui	Rain water	19 or 20 Mar.
6	Jingzhe	Waking of insects	6 or 7 MAr.
7	Chunfen	Spring equinox	21 or 22 Mar.
8	Qingming	Pure brightness	5 or 6 Apr.
9	Guyu	Grain rain	20 or 21 Apr.
10	Lixia	Start of summer	6 or 7 May
11	Xiaoman	Forming of grain	21 or 22 May
12	Manhzhong	Grain in ear	6 or 7 June
13	Xiazhi	Summer solstice	22 or 23 June
14	Xiaoshu	Slight heat	7 or 8 July
15	Dashu	Great heat	23 or 24 July
16	Liqui	Start of autumn	8 or 9 Aug.
17	Chushu	Limit if heat	23 or 24 Aug.
18	Bailu	White dew	8 or 9 Sept.
19	Qiufen	Autumn equinox	23 or 24 Sept.
20	Hanlu	Cold dew	9 or 10 Oct.
21	Shuangjiang	Frost's descent	24 or 25 Oct.
22	Lidong	Start of winter	8 or 9 Nov.
23	Xiaoxue	Slight snow	23 or 24 Nov.
24	Daxue	Great snow	7 or 8 Dec.

Names of the months

The first month was called zhengyue, "correct month," among other names over the millenia. All the others' names are simply numbers.

Months were also referred to by their place in the season: mengchun being the first month of a season, then zhongchun and jichun.

Divisions of the month

The month was divided into 3 sanxun, each of ten days: shangxun, zhongxun, and xiaxun.

Names of the days

Days were also named using the same 60 day cycle used for years; one cycle made two months.

Solar year calendar

In addition to the civil calendar, both China and Japan had a calendar based on the solar year and used largely by farmers. It divided the solar year into 12 parts, each about 30.44 days long.

For Further Reading

Gaimusho Bunshoka.
Nihon gaikō bunsho: Kindai in'yōreki taishō hyō.
(1951?)

Gives the corresponding Western date for every day in the Chinese and Japanese lunar calendars between ad 1700 and 1911.