Editing Chinese calendar (section)

==History==
The Chinese calendar system has a long history, which has traditionally been associated with specific [[Dynasties of China|dynastic periods]]. Various individual calendar types have been developed with different names. In terms of historical development, some of the calendar variations are associated with dynastic changes along a spectrum beginning with a prehistorical/mythological time to and through well attested historical dynastic periods. Many individuals have been associated with the development of the Chinese calendar, including researchers into underlying astronomy; and, furthermore, the development of instruments of observation are historically important. Influences from India, Islam, and Jesuits also became significant.

===Solar calendars===
[[File:Five Phases and Four Seasons Calendar.png|thumb|alt=See caption|Five-phase and four-quarter calendars]]
The traditional Chinese lunisolar calendar was developed between 771 BCE and 476 BCE, during the [[Spring and Autumn period]] of the [[Eastern Zhou]] dynasty. Solar calendars were used before the [[Zhou dynasty]] period, along with the basic sexagenary system.

One version of the solar calendar is the five-elements (or phases) calendar ({{zh-no-labels|s=五行历|t=五行曆|p=wǔxíng lì}}), which derives from the [[Wuxing (Chinese philosophy)|Wu Xing]]. A 365-day year was divided into five phases of 72 days, with each phase preceded by an [[Intercalation (timekeeping)|intercalary]] day associated with the claimed beginning of the following 72 day period of domination by the next Wu Xing element; thus, the five phases each begin with a governing-element day ({{lang|zh|行御}}), followed by a 72 day period characterized by the ruling element. Years began on a {{zh-no-labels|p=jiǎzǐ|c=甲子|out=p}} day and a 72-day wood phase, followed by a {{zh-no-labels|c=丙子|p=bǐngzǐ|out=p}} day and a 72-day fire phase; a {{zh-no-labels|p=wùzǐ|c=戊子|out=p}} day and a 72-day earth phase; a {{zh-no-labels|p=gēngzǐ|c=庚子|out=p}} day and a 72-day metal phase, and a {{zh-no-labels|p=rénzǐ|c=壬子|out=p}} day followed by a water phase.<ref name="Guanzi 41">{{cite wikisource |title=zh:管子|trans-title=[[Guanzi (text)|Guanzi]] |chapter=第41篇五行|trans-chapter=Chapter 41: Five Elements|wslanguage=zh}}</ref> Each phase consisted of two three-week months, making each year ten months long. Other days were tracked using the [[Yellow River Map]] (''He Tu'').

Another version is a four-quarters calendar ({{zh|labels=no|s=四时八节历|t=四時八節曆|l=four seasons eight solar terms calendar|p=sìshí bājié lì}}, or {{zh|labels=no|t=四分曆|s=四分历|p=sìfēn lì|l=quarters calendar}}). The weeks were ten days long, with one month consisting of three weeks. A year had 12 months, with a ten-day week [[Intercalation (timekeeping)|intercalated]] in summer as needed to keep up with the tropical year. The 10 [[Heavenly Stems]] and 12 [[Earthly Branches]] were used to mark days.<ref name="Guanzi 40">{{cite wikisource |title=管子|trans-title=[[Guanzi (text)|Guanzi]] |chapter=第40篇四時|trans-chapter=Chapter 40: Four Sections|wslanguage=zh}}</ref>

A third version is the balanced calendar ({{zh|labels=no|t=調曆|s=调历 |p=tiáo lì}}). A year was 365.25 days, and a month was 29.5 days. After every 16th month, a half-month was intercalated. According to [[oracle bone]] records, the [[Shang dynasty]] calendar ({{Circa|1600|1046}} BCE) was a balanced calendar with 12 to 14 months in a year; the month after the winter solstice was {{tlit|zh|pinyin|Zhēngyuè}}.<ref>{{cite web |url=http://www.newsmth.net/bbsanc.php?path=/groups/sci.faq/Astronomy/bw/all2/bk37k/M.1275291864.z0&ap=353 |script-title=zh:中国农历发展简史 |trans-title=A brief history of the development of Chinese Lunar calendar |format=PDF |access-date=24 February 2016 |archive-date=26 February 2021 |archive-url=https://web.archive.org/web/20210226064642/https://www.newsmth.net/bbsanc.php?path=%2Fgroups%2Fsci.faq%2FAstronomy%2Fbw%2Fall2%2Fbk37k%2FM.1275291864.z0&ap=353 |url-status=dead }}</ref>

A solar calendar called the [[Tung Shing]], the ''Yellow Calendar'' or  ''Imperial Calendar'' (both alluding to [[Yellow Emperor]]) continued to see use as an almanac and agricultural guide throughout Chinese history.<ref>{{cite book |first=Martin |last=Palmer |title=T'ung Shu: the Ancient Chinese Almanac |publisher=Shambhala |location=Boston |year=1986 |isbn=9780394742212 |pages=9–10}}</ref>

===Lunisolar calendars by dynasty===
{{See also|Lunisolar calendar}}
Lunisolar calendars involve correlations of the cycles of the sun (solar) and the moon (lunar). 

====Zhou dynasty====
The first [[Lunisolar calendar|lunisolar]] calendar was the ''Zhou'' calendar ({{zh|labels=no|t=周曆|s=周历}}), introduced under the [[Zhou dynasty]] (1046 BCE – 256 BCE). This calendar sets the beginning of the year at the day of the new moon before the winter solstice.

====Competing Warring states calendars====
{{See also|Warring States period}}
Several competing [[Lunisolar calendar|lunisolar]] calendars were introduced as Zhou devolved into the Warring States, especially by states fighting Zhou control during the [[Warring States period]] (perhaps 475 BCE - 221 BCE).
From the [[Warring States period]] (ending in 221 BCE), six especially significant calendar systems are known to have begun to be developed. Later on, during their future course in history, the modern names for the ancient six calendars were also developed: ''Huangdi, Yin, Zhou, Xia, Zhuanxu,'' and ''Lu''.<ref>[https://ytliu0.github.io/ChineseCalendar/guliuli.html Yuk Tung Liu, 2018–2024, at GitHub]</ref>

Modern historical knowledge and records are limited for the earlier calendars. These calendars are known as the ''six ancient calendars'' ({{zh|labels=no|t=古六曆|s=古六历}}), or quarter-remainder calendars, ({{zh|labels=no|t=四分曆|s=四分历|p=sìfēnlì}}), since all calculate a year as {{frac|365|1|4}} days long. Months begin on the day of the new moon, and a year has 12 or 13 months. Intercalary months (a 13th month) are added to the end of the year.

{{anchor|Lu calendar}}
The state of [[Lu (state)|Lu]] issued its own ''Lu calendar'' ({{zh|labels=no|t=魯曆|s=鲁历}}).

{{anchor|Xia calendar}}
The state of [[Jin (Chinese state)|Jin]] issued the ''[[Xia dynasty|Xia]] calendar'' ({{zh|labels=no|t=夏曆|s=夏历}})<ref name="Petersen">{{cite journal |last=Petersen |first=Jens Østergård |year=1992 |title=The Taiping Jing and the AD 102 Clepsydra Reform |journal=Acta Orientalia |volume=53 |pages=122–158 |url=https://www.academia.edu/12945035 |access-date=2 October 2018 |archive-date=11 January 2022 |archive-url=https://web.archive.org/web/20220111191102/https://www.academia.edu/12945035 |url-status=live }}</ref> with a year beginning on the day of the new moon nearest the [[March equinox]].

{{anchor|Zhuanxu calendar}}
The state of [[Qin (state)|Qin]] issued the ''[[Zhuanxu]] calendar'' ({{zh|labels=no|t=顓頊曆|s=颛顼历}}), with a year beginning on the day of the new moon nearest the [[winter solstice]]. 
{{anchor|Qiang calendar|Dai calendar}}
The ''Qiang'' and ''Dai calendars'' are modern versions of the Zhuanxu calendar, used by highland peoples.

{{anchor|Yin calendar}}
The [[Song (state)|Song state]]'s ''[[Shang dynasty|Yin]] calendar'' ({{zh|labels=no|t=殷曆|s=殷历}}) began its year on the day of the new moon after the winter solstice.

====Qin and early Han dynasties====
{{See also|Qin dynasty|Han dynasty}}
{{anchor|Qin calendar}}
After [[Qin Shi Huang]] unified China under the Qin dynasty in 221 BCE, the ''Qin calendar'' ({{zh|labels=no|t=秦曆|s=秦历}}) was introduced. 
It followed most of the rules governing the [[#Zhuanxu calendar|Zhuanxu calendar]], but the month order was that of the [[#Xia calendar|Xia calendar]]; the year began with month 10 and ended with month 9, analogous to a Gregorian calendar beginning in October and ending in September. The intercalary month, known as ''the second'' {{zh|labels=no|t=後九月|s=后九月|p=Jiǔyuè|out=p}}, was placed at the end of the year. The Qin calendar was used going into the Han dynasty.

====Han dynasty Tàichū calendar====
{{Further|Han dynasty|Emperor Wu of Han#Calendar reform}}
{{anchor|Tàichū calendar|Taichu calendar}}
[[Emperor Wu of Han]] {{reign|141|87 BCE}} introduced reforms in the seventh of the eleven named eras of his reign, {{zh|labels=no|t=太初|s=太初|p=Tàichū|l=Grand Beginning|out=p}}, 104 BCE – 101 BCE. His ''{{tlit|zh|pinyin|Tàichū}} calendar'' ({{zh|labels=no|t=太初曆|s=太初历|l=grand beginning calendar}}) defined a solar year as {{frac|365|385|1539}} days (365;06:00:14.035), and the lunar month had {{frac|29|43|81}} days (29;12:44:44.444). 
Since <math>\left(365+\frac{385}{1539}\right)\times19=\left(29+\frac{43}{81}\right)\times \left(19\times 12 + 7 \right)
 </math> the 19 years cycle used for the 7 additional months was taken as an exact one, and not as an approximation.

This calendar introduced the 24 [[solar term]]s, dividing the year into 24 equal parts of 15° each. Solar terms were paired, with the 12 combined periods known as ''climate terms''. The first solar term of the period was known as a pre-climate ({{lang|zh|节气}}), and the second was a mid-climate ({{lang|zh|中气}}). Months were named for the mid-climate to which they were closest, and a month without a mid-climate was an intercalary month.<ref>{{Cite web |title=Chinese calendar {{!}} Lunar Year, Solar Eclipses & Solstices {{!}} Britannica |url=https://www.britannica.com/science/Chinese-calendar |access-date=2024-06-23 |website=www.britannica.com |language=en}}</ref>

The Taichu calendar established a framework for traditional calendars, with later calendars adding to the basic formula.

====Northern and Southern Dynasties Dàmíng calendar====
{{See also|Northern and Southern dynasties#Southern dynasties}}
{{anchor|Dàmíng calendar|Daming calendar}}
The ''Dàmíng calendar'' ({{zh|labels=no|t=大明曆|s=大明历|l=brightest calendar}}), created in the [[Northern and Southern Dynasties]] by [[Zu Chongzhi]] (429 CE – 500 CE), introduced the equinoxes.

====Tang dynasty Wùyín Yuán calendar====
{{See also|Tang dynasty}}{{Further|Syzygy (astronomy)}}
{{anchor|Wùyín Yuán calendar|Wuyin Yuan calendar}}
The use of [[Syzygy (astronomy)|syzygy]] to determine the lunar month was first described in the [[Tang dynasty]] ''{{tlit|zh|pinyin|Wùyín Yuán}} calendar'' ({{zh|labels=no|t=戊寅元曆|s=戊寅元历|l=earth tiger epoch calendar}}).

====Yuan dynasty Shòushí calendar====
{{See also|Yuan dynasty}}
{{anchor|Shòushí calendar|Shoushi calendar}}
The [[Yuan dynasty]] ''Shòushí calendar'' ({{zh|labels=no|t=授時曆|s=授时历|l=season granting calendar}}) used [[spherical trigonometry]] to find the length of the [[tropical year]].<ref>{{Cite book|last=Needham |first=Joseph |orig-year=1954 |title=Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth |volume=3 |date=1986 |pages=109–110|bibcode=1959scc3.book.....N }}</ref><ref>{{cite book |last=Ho |first=Peng Yoke |date=2000 |title=Li, Qi, and Shu: An Introduction to Science and Civilization in China |location=Mineola |publisher=Dover Publications |isbn=978-0-486-41445-4 |page=105}}</ref><ref>{{cite book |last=Restivo |first=Sal |date=1992 |title=Mathematics in Society and History: Sociological Inquiries |location=Dordrecht |publisher=Kluwer Academic Publishers |isbn=978-1-4020-0039-3 |page=32}}</ref>
The calendar had a 365.2425-day year, identical to the [[Gregorian calendar]].<ref>{{cite book |editor=Asiapac Editorial |date=2004 |title=Origins of Chinese Science and Technology |translator1=Yang Liping |translator2=Y.N. Han |location=Singapore |publisher=Asiapac Books |isbn=978-981-229-376-3 |page=132}}</ref>

==== Ming and Qing Shíxiàn calendar ====
{{Main|Chongzhen calendar}}
{{anchor|Shíxiàn calendar|Shixian calendar|Chongzhen calendar}}
From 1645 to 1913 the ''{{tlit|zh|pinyin|Shíxiàn}}'' or ''Chongzhen calendar'' was developed. During the late [[Ming dynasty]], the Chinese Emperor appointed [[Xu Guangqi]] in 1629 to be the leader of the [[Chongzhen calendar|Shixian calendar]] reform. Assisted by Jesuits, he translated Western astronomical works and introduced new concepts, such as those of [[Nicolaus Copernicus]], [[Johannes Kepler]], [[Galileo Galilei]], and [[Tycho Brahe]]; however, the new calendar was not released before the end of the dynasty. 

In the early [[Qing dynasty]], [[Johann Adam Schall von Bell]] submitted the calendar which was edited by the lead of [[Xu Guangqi]] to the [[Shunzhi Emperor]].<ref>{{cite journal |last1=Stone |first1=Richard |title=Scientists Fete China's Supreme Polymath |journal=Science |date=2 November 2007 |volume=318 |issue=5851 |pages=733 |doi=10.1126/science.318.5851.733 |pmid=17975042 |s2cid=162156995 |doi-access=free }}</ref> 
The Qing government issued it as the ''{{tlit|zh|pinyin|Shíxiàn}} (seasonal) calendar''. In this calendar, the [[solar term]]s are 15° each along the [[ecliptic]] and it can be used as a [[solar calendar]]. However, the length of the climate term near the [[Apsis|perihelion]] is less than 30 days and there may be two mid-climate terms. The {{tlit|zh|pinyin|Shíxiàn}} calendar changed the mid-climate-term rule to "decide the month in sequence, except the intercalary month."<ref>{{Cite web |script-title=zh:本世纪仅有4次！闰二月为何少见？-新华网 |url=http://www.news.cn/tech/2023-03/21/c_1129450471.htm |access-date=2023-05-02 |website=www.news.cn |archive-date=2 May 2023 |archive-url=https://web.archive.org/web/20230502045811/http://www.news.cn/tech/2023-03/21/c_1129450471.htm |url-status=live }}</ref> 

The present "traditional calendar" follows the Shíxiàn calendar, except:
# The baseline is Chinese Standard Time, rather than Beijing local time.
# Modern astronomical data, rather than mathematical calculations, is used.

====Modern Chinese calendar====

The Chinese calendar lost its place as the country's official calendar at the beginning of the 20th century,<ref name="Sun Yat-sen">{{cite book |author=Sun Yat-sen |url=https://confuciusinstitute.unl.edu/Week%205.2%20-%20Sun%20Yat-sen%20-%20Inaugural%20Address%20of%20the%20Provisional%20President%28January%201%2C%201912%29.pdf |title= |date=1982 |publisher={{lang|zh|中华书局}} |volume=v. 2 |location=Beijing |page=5 |script-title=zh:孙中山全集 |trans-title=The Complete Works of Sun Yat-sen |script-chapter=zh:临时大总统改历改元通电 |trans-chapter=Provisional President's open telegram on calendar change and era change |access-date=2 May 2023 |orig-year=Telegram originally sent 1 January 1912 |archive-url=https://web.archive.org/web/20230129194502/https://confuciusinstitute.unl.edu/Week%205.2%20-%20Sun%20Yat-sen%20-%20Inaugural%20Address%20of%20the%20Provisional%20President%28January%201%2C%201912%29.pdf |archive-date=29 January 2023 |url-status=live}}</ref> its use has continued. 

{{anchor|Republic of China Calendar}}
The ''Republic of China Calendar'' published by the [[Beiyang government]] of the Republic of China still listed the dates of the Chinese calendar in addition to the Gregorian calendar. 

{{anchor|Kuómín calendar|Kuomin calendar}}
In 1929, the [[Nationalist government]] tried to ban the traditional Chinese calendar. The ''{{tlit|zh|pinyin|Kuómín}} Calendar'' published by the government no longer listed the dates of the Chinese calendar. 
However, Chinese people were used to the traditional calendar and many traditional customs were based on the Chinese calendar. The ban failed and was lifted in 1934.<ref>{{Cite web |title=Rules for the Chinese Calendar |url=https://ytliu0.github.io/ChineseCalendar/rules.html |url-status=live |archive-url=https://web.archive.org/web/20230220003057/https://ytliu0.github.io/ChineseCalendar/rules.html |archive-date=20 February 2023 |access-date=2023-02-20 |website=ytliu0.github.io}}</ref>

{{anchor|Wànniánlì calendar|Wannianli calendar}}
The latest Chinese calendar was "New Edition of {{tlit|zh|pinyin|Wànniánlì}}, revised edition", edited by Beijing Purple Mountain Observatory, People's Republic of China.<ref>{{Cite book |last=CAS |first=Purple Mountain Observatory |title=New Edition of Wànniánlì, revised edition |publisher=Popular Science Press |year=1986}}</ref>

In China, the modern calendar is defined by the [[National Standards of the People's Republic of China|Chinese national standard]] GB/T 33661–2017,<ref>{{Cite web |script-title=zh:国家标准 {{!}} GB/T 33661-2017 |url=http://c.gb688.cn/bzgk/gb/showGb?type=online&hcno=E107EA4DE9725EDF819F33C60A44B296 |access-date=28 September 2023 |archive-date=28 September 2023 |archive-url=https://web.archive.org/web/20230928111539/http://c.gb688.cn/bzgk/gb/showGb?type=online&hcno=E107EA4DE9725EDF819F33C60A44B296 |url-status=live }}</ref> "Calculation and Promulgation of the Chinese Calendar", issued by the [[Standardization Administration of China]] on 12 May 2017.

Although modern-day China uses the [[Gregorian calendar]], the traditional Chinese calendar governs holidays, such as the [[Chinese New Year]] and [[Lantern Festival]], in both China and [[overseas Chinese]] communities. It also provides the traditional Chinese nomenclature of dates within a year which people use to select auspicious days for [[Auspicious wedding dates|weddings]], funerals, moving or starting a business.<ref>{{Cite journal |last1=Xiao |first1=Fang |last2=Zhang |first2=Juwen |last3=Long |first3=Bill |date=2017 |title=The Predicament, Revitalization, and Future of Traditional Chinese Festivals |jstor=44790971 |journal=Western Folklore |volume=76 |issue=2 |pages=181–196 }}</ref> The evening state-run news program ''[[Xinwen Lianbo]]'' in the [[People's Republic of China]] continues to announce the months and dates in both the Gregorian and the traditional lunisolar calendar.

To optimize the Chinese calendar, astronomers have proposed a number of changes. [[Kao Ping-tse]] ({{zh|labels=no|c=高平子}}; 1888–1970), a Chinese astronomer who co-founded the [[Purple Mountain Observatory]], proposed that month numbers be calculated before the new moon and solar terms to be rounded to the day. Since the intercalary month is determined by the first month without a mid-climate and the mid-climate time varies by time zone, countries that adopted the calendar but calculate with their own time could vary from the time in China.<ref>{{Cite book |last=Martzloff |first=Jean-Claude |url=https://books.google.com/books?id=SYj2DAAAQBAJ&dq=Gao+Pingzi+month+numbers&pg=PA242 |title=Astronomy and Calendars – The Other Chinese Mathematics: 104 BCE - 1644 CE |date=2016-09-01 |publisher=Springer |isbn=978-3-662-49718-0 |language=en |access-date=19 October 2022 |archive-date=8 October 2023 |archive-url=https://web.archive.org/web/20231008220827/https://books.google.com/books?id=SYj2DAAAQBAJ&dq=Gao+Pingzi+month+numbers&pg=PA242 |url-status=live }}</ref>

===Contributions from Chinese astronomy===
{{Main|Chinese astronomy}}

The Chinese calendar has been a development involving much observation and calculation of the apparent movements of the Sun, Moon, planets, and stars, as observed from Earth.

Many Chinese astronomers have contributed to the development of the Chinese calendar. Many were of the scholarly or ''shi'' class ({{zh |t = 士|s =士|p=shì}}), including writers of history, such as [[Sima Qian]].

Notable Chinese astronomers who have contributed to the development of the calendar include [[Gan De]], [[Shi Shen]], and [[Zu Chongzhi]]

{{further|Chinese star maps|Armillary sphere}}
Early technological developments aiding in calendar development include the development of the [[gnomon]].  Later technological developments useful to the calendar system include [[Chinese star names|naming, numbering]] and mapping of the sky, the development of analog computational devices such as the armillary sphere and the water clock, and the establishment of observatories.