Editing Chinese calendar (section)

== Sexagenary system==
Several coding systems are used to avoid ambiguity. The [[Heavenly Stems]] is a [[decimal]] system. The [[Earthly Branches]], a [[duodecimal]] system, mark dual hours ({{zh|labels=no|p=shí|t={{linktext|時}}|s={{linktext|时}}}} or {{zh|labels=no|p=shíchen|t={{linktext|時辰}}|s={{linktext|时辰}}}}) and climatic terms. The 12 characters progress from the first day with the same branch as the month (first {{tlit|zh|pinyin|Yín}} day ({{linktext|寅|日|lang=zh}}) of {{tlit|zh|pinyin|Zhēngyuè}}; first {{tlit|zh|pinyin|Mǎo}} day ({{linktext|卯|日|lang=zh}}) of {{tlit|zh|pinyin|Èryuè}}), and count the days of the month.

{{Main|Sexagenary cycle}}
Years, months, days of the month and hours could traditionally numbered by the terminology of the Chinese sexagenary cycle.

The [[Sexagenary cycle|stem-branches]] is a [[sexagesimal]] system. The Heavenly Stems and Earthly Branches make up [[Sexagenary cycle|60 stem-branches]]. The stem branches mark days and years. The five [[Wuxing (Chinese philosophy)|Wu Xing]] elements are assigned to each stem, branch, or stem branch.

{| class="wikitable" border="1"
! rowspan="2" | Heavenly<br />Stem !! colspan="2" | Meaning
|-
! Original meaning !! Modern
|-
|{{lang|zh|甲}}|| [[turtle shell]] || ''first (book I, person A etc.)'', ''methyl group'', helmet, armor, words related to beetles, crustaceans, fingernails, toenails
|-
|{{lang|zh|乙}}|| [[fishguts]] || ''second (book II, person B etc.)'', ''ethyl group'', twist
|-
|{{lang|zh|丙}}|| [[caudal fin|fishtail]]{{efn|Wenlin Dictionary: Picture of a fish tail.{{Full citation needed|date=February 2025}}}}|| ''third'', bright, fire, fishtail (rare)
|-
|{{lang|zh|丁}}|| [[Nail (fastener)|nail]] || ''fourth'', male adult, robust, T-shaped, to strike, a surname
|-
|{{lang|zh|戊}}|| [[halberd]] || (not used)
|-
|{{lang|zh|己}}|| threads on a loom{{efn|Wenlin Dictionary: {{lang|zh|己}} may have depicted [[Thread (yarn)|thread]] on a [[loom]]; an ancient meaning was 'unravel threads', which was later written {{lang|zh|紀}} jì. {{lang|zh|己}} was borrowed both for the word jǐ 'self', and for the name of the sixth Heavenly Stem ({{lang|zh|天干}}).{{Full citation needed|date=February 2025}}}} || self
|-
|{{lang|zh|庚}}|| evening star || age (of person)
|-
|{{lang|zh|辛}}|| to offend superiors<ref>Wenlin Dictionary: "The seal has {{lang|zh|𢆉}} 'knock against, offend' below, and {{lang|zh|亠}} above; the scholastic commentators say: to offend ({{lang|zh|亠}} = ) {{lang|zh|上}} the superiors"{{Full citation needed|date=February 2025}}</ref> || bitter, piquant, toilsome
|-
|{{lang|zh|壬}}|| burden{{efn|Wenlin Dictionary: {{lang|zh|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 {{lang|zh|扁担}} biǎndan). Now the character {{lang|zh|任}} rèn has the meaning of carrying a burden, and the original character {{lang|zh|壬}} is used only for the ninth of the ten heavenly stems ({{lang|zh|天干}}).{{Full citation needed|date=February 2025}}}} || to shoulder, to trust with office
|-
|{{lang|zh|癸}}|| grass for libation{{efn|Wenlin Dictionary: {{lang|zh|癶}} "stretch out the legs" + {{lang|zh|天}}; The nicely disposed grass, on which the Ancients poured the libations offered to the Manes{{Full citation needed|date=February 2025}}}}|| (not used)
|}

{|class="wikitable"
!rowspan=2|&nbsp;
!rowspan=2|Earthly<br />Branch
!colspan=3|Chinese
!rowspan=2|Direction
!rowspan=2|Season
!rowspan=2|Lunar Month
!rowspan=2|Double Hour
|-
!Mandarin<br />[[Zhuyin]]
!Mandarin<br />[[Pinyin]]
|-tr align="center"
||1||{{linktext|子|lang=zh}}||{{lang|zh-Bopo|ㄗˇ}}||{{tlit|zh|pinyin|zǐ}}||{{lang|zh|鼠}}<br />[[Rat (zodiac)|Rat]]||0° (north)||rowspan="2"|winter||Month 11||11&nbsp;pm to 1&nbsp;am (midnight)
|-tr align="center"
||2||{{linktext|丑|lang=zh}}||{{lang|zh-Bopo|ㄔㄡˇ}}||{{tlit|zh|pinyin|chǒu}}||{{lang|zh|牛}} <br /> [[Ox (zodiac)|Cow]]||30°||Month 12||1am to 3&nbsp;am
|-tr align="center"
||3||{{linktext|寅|lang=zh}}||{{lang|zh-Bopo|ㄧㄣˊ}}||{{tlit|zh|pinyin|yín}}||{{lang|zh|虎}}<br />[[Tiger (zodiac)|Tiger]]||60°||td rowspan="3"|spring||Month 1||3&nbsp;am to 5&nbsp;am
|-tr align="center"
||4||{{linktext|卯|lang=zh}}||{{lang|zh-Bopo|ㄇㄠˇ}}||{{tlit|zh|pinyin|mǎo}}||{{lang|zh|兎}}<br />[[Rabbit (zodiac)|Rabbit]]||90° (east)||Month 2||5&nbsp;am to 7&nbsp;am
|-tr align="center"
||5||{{linktext|辰|lang=zh}}||{{lang|zh-Bopo|ㄔㄣˊ}}||{{tlit|zh|pinyin|chén}}||{{lang|zh|竜 (龍)}}<br />[[Dragon (zodiac)|Dragon]]||120°||Month 3||7&nbsp;am to 9&nbsp;am
|-tr align="center"
||6||{{linktext|巳|lang=zh}}||{{lang|zh-Bopo|ㄙˋ}}||{{tlit|zh|pinyin|sì}}||{{lang|zh|蛇}}<br />[[Snake (zodiac)|Snake]]||150°||td rowspan="3"|summer||Month 4||9&nbsp;am to 11&nbsp;am
|-tr align="center"
||7||{{linktext|午|lang=zh}}||{{lang|zh-Bopo|ㄨˇ}}||{{tlit|zh|pinyin|wǔ}}||{{lang|zh|馬}}<br />[[Horse (zodiac)|Horse]]||180° (south)||Month 5||11&nbsp;am to 1&nbsp;pm (noon)
|-tr align="center"
||8||{{linktext|未|lang=zh}}||{{lang|zh-Bopo|ㄨㄟˋ}}||{{tlit|zh|pinyin|wèi}}||{{lang|zh|羊}}<br />[[Goat (zodiac)|Sheep]]||210°||Month 6||1&nbsp;pm to 3&nbsp;pm
|-tr align="center"
||9||{{linktext|申|lang=zh}}||{{lang|zh-Bopo|ㄕㄣ}}||{{tlit|zh|pinyin|shēn}}||{{lang|zh|猿}}<br />[[Monkey (zodiac)|Monkey]]||240°||td rowspan="3"|autumn||Month 7||3&nbsp;pm to 5&nbsp;pm
|-tr align="center"
||10||{{linktext|酉|lang=zh}}||{{lang|zh-Bopo|ㄧㄡˇ}}||{{tlit|zh|pinyin|yǒu}}||{{lang|zh|鶏 (鳥)}} <br /> [[Rooster (zodiac)|Chicken]]||270° (west)||Month 8||5&nbsp;pm to 7&nbsp;pm
|-tr align="center"
||11||{{linktext|戌|lang=zh}}||{{lang|zh-Bopo|ㄒㄩ}}||{{tlit|zh|pinyin|xū}}||{{lang|zh|犬}}<br />[[Dog (zodiac)|Dog]]||300°||Month 9||7&nbsp;pm to 9&nbsp;pm
|-tr align="center"
||12||{{linktext|亥|lang=zh}}||{{lang|zh-Bopo|ㄏㄞˋ}}||{{tlit|zh|pinyin|hài}}||{{lang|zh|猪}}<br />[[Wild boar]]||330°||winter||Month 10||9&nbsp;pm to 11&nbsp;pm
|}

For example, the year from 12 February 2021 to 31 January 2022 was a {{tlit|zh|pinyin|Xīnchǒu}} year ({{linktext|辛丑|年|lang=zh}}) of 12 months or 354 days. The 60 stem-branches have been used to mark the year since the [[Shang dynasty]] (1600 BCE – 1046 BCE). Astrologers knew that the orbital period of [[Jupiter]] is about 12×361 = 4332 days, which they divided into 12 years ({{zh|labels=no|s=岁|t=歲|p=suì}}) of 361 days each. The stem-branches system solved the era system's problem of unequal reign lengths.
[[File:ROC Gazette by Hubei Military Government 19111015.jpg|thumb|Hubei military government founded ROC [[Gazetteer|Gazette]] ({{lang|zh|中華民國公報}}), dated YE 4609-10-15 ({{lang|zh|黃帝紀元4609年10月15日}}, yyyy-mm-dd)]] 

{{See also|Month|Lunar month}}

Current naming conventions use numbers as the month names, although each month is also associated with one of the twelve [[Earthly Branches]]. Correspondences with Gregorian dates are approximate and should be used with caution. Many years have intercalary months.

Historically, Chinese had days of the month numbered with the 60 stem-branches: {{Blockquote| text={{lang|zh|天聖元年…{{linktext|二月}}…{{linktext|丁|巳}}，奉安太祖、太宗御容于南京鴻慶宮}}. <br />{{tlit|zh|pinyin|[[Tiansheng Era (Song)|''Tiānshèng'']]}} 1st year…{{tlit|zh|pinyin|Èryuè}}…{{tlit|zh|pinyin|Dīngsì}}, the emperor's funeral was at his temple, and the imperial portrait was installed in Nanjing's ''Hongqing Palace''. |title=[[History of Song Dynasty]]|sign=|source={{cite wikisource|title=宋史|trans-title=[[History of Song Dynasty]]|chapter=卷009|trans-chapter=Volume 9|wslanguage=zh}}}}

Fortune-tellers identify the [[heavenly stem]] and [[earthly branch]] corresponding to a particular day in the month, and those corresponding to its month, and those to its year, to determine the [[Four Pillars of Destiny]] associated with it, for which the [[Tung Shing]], also referred to as the [[Chinese Almanac]] of the year, or the [[Huangli]], and containing the essential information concerning [[Chinese astrology]], is the most convenient publication to consult. Days rotate through a [[sexagenary cycle]] marked by coordination between [[heavenly stem]]s and [[earthly branch]]es, hence the referral to the [[Four Pillars of Destiny]] as, "Bazi", or "[[Birth Time Eight Characters]]", with each pillar consisting of a character for its corresponding heavenly stem, and another for its earthly branch. Since [[Huangli]] days are [[sexagenary cycle|sexagenaric]], their order is quite independent of their numeric order in each month, and of their numeric order within a week (referred to as [[True Animals]] in relation to the [[Chinese zodiac]]). Therefore, it does require painstaking calculation for one to arrive at the [[Four Pillars of Destiny]] of a particular given date, which rarely outpaces the convenience of simply consulting the [[Huangli]] by looking up its [[Gregorian calendar|Gregorian]] date.

The [[Tang dynasty]] used the Earthly Branches to mark the months from December 761 to May 762.<ref name="new book of tang">{{cite wikisource|title=新唐書|trans-title=[[New Book of Tang]]|chapter=卷006|trans-chapter=Volume 6|wslanguage=zh|quote={{lang|zh|上元…。二年……，九月壬寅，大赦，去「乾元大圣光天文武孝感」号，去「上元」号，称元年，以十一月为岁首，月以斗所建辰为名。…。<br />元年建子月癸巳[2]，…。己亥[9]，…。丙午[16]，…。己酉[29]，…。庚戌[30]，…。[初一壬午大雪，十七冬至]<br/>建丑月辛亥[1]，…。己未[9]，…。乙亥[25]，…。[初一辛亥，初三小寒，十八大寒]<br/>宝应元年建寅月甲申[4]，…。乙酉[5]，…。丙戌[3]，…。甲辰[24]，…。戊申[28]，…。[初一辛巳，初三立春，十八雨水]<br/>建卯月辛亥[1]，…。壬子[2]，…。癸丑[3]，…。乙丑[15]，…。戊辰[18]，…。庚午[20]，…。壬申[22]，…。[初一辛亥，初四惊蛰，十九春分]<br/>建辰月壬午[3]，…。甲午[5]，…。戊申[19]，…。[初一庚辰，初五清明，二十谷雨]<br/>建巳月庚戌[1]，…。壬子[3]，…。甲寅[5]，…。乙丑[16]，…。大赦，改元年为宝应元年，复以正月为岁首，建巳月为四月。丙寅，…。[初一庚戌，初五甲寅立夏]。}}}}</ref> Over this period, the year began with the winter solstice.

{{main|Traditional Chinese timekeeping}}
[[File:Chinese time.png|thumb|alt=See caption|Explanatory chart for traditional Chinese time]]
China has used the Western hour-minute-second system to divide the day since the [[Qing dynasty]].<ref name="units of time">{{cite journal |last1=Sôma |first1=Mitsuru |last2=Kawabata |first2=Kin-aki |last3=Tanikawa |first3=Kiyotaka |title=Units of Time in Ancient China and Japan |journal=Publications of the Astronomical Society of Japan |date=25 October 2004 |volume=56 |issue=5 |pages=887–904 |doi=10.1093/pasj/56.5.887 }}</ref> Several systems were in use historically; systems using multiples of twelve and ten were popular, since they could be easily counted and aligned with the Heavenly Stems and Earthly Branches.