The Byzantine calendar called "Creation Era of Constantinople" or "Era of the World", was the calendar used by the Eastern Orthodox Church from c. 691 to 1728 in the Ecumenical Patriarchate. It was the official calendar of the Byzantine Empire from 988 to 1453, of Kievan Rus' and Russia from c. 988 to 1700. Since "Byzantine" is a historiographical term, the original name uses the noun "Roman" as it was how the Eastern Roman Empire continued calling itself; the calendar was based on the Julian calendar, except that the year started on 1 September and the year number used an Anno Mundi epoch derived from the Septuagint version of the Bible. It placed the date of creation at 5509 years before the Incarnation, was characterized by a certain tendency, a tradition among Jews and early Christians to number the years from the calculated foundation of the world, its Year One, marking the supposed date of creation, was September 1, 5509 BC, to August 31, 5508 BC. It is not known when; the first appearance of the term is in the treatise of a certain "monk and priest", who mentions all the main variants of the "World Era" in his work.
Georgios argues that the main advantage of the World era is the common starting point of the astronomical lunar and solar cycles, of the cycle of indictions, the usual dating system in Byzantium since the 6th century. He already regards it as the most convenient for the Easter computus. Complex calculations of the 19-year lunar and 28-year solar cycles within this world era allowed scholars to discover the cosmic significance of certain historical dates, such as the birth or the crucifixion of Jesus; this date underwent minor revisions before being finalized in the mid-7th century, although its precursors were developed c. AD 412. By the second half of the 7th century, the Creation Era was known in Western Europe, at least in Great Britain. By the late 10th century around AD 988, when the era appears in use on official government records, a unified system was recognized across the Eastern Roman world; the era was calculated as starting on September 1, Jesus was thought to have been born in the year 5509 since the creation of the world.
Historical time was thus calculated from the creation, not from Christ's birth, as in the west after the Anno Domini system was adopted between 6th and 9th centuries. The Eastern Church avoided the use of the Anno Domini system of Dionysius Exiguus, since the date of Christ's birth was debated in Constantinople as late as the 14th century. Otherwise the Byzantine calendar was identical to the Julian Calendar except that: the names of the months were transcribed from Latin into Greek; the leap day of the Byzantine calendar was obtained in an identical manner to the bissextile day of the original Roman version of the Julian calendar, by doubling the sixth day before the calends of March, i.e. by doubling 24 February. The Byzantine World Era was replaced in the Orthodox Church by the Christian Era, utilized by Patriarch Theophanes I Karykes in 1597, afterwards by Patriarch Cyril Lucaris in 1626, formally established by the Church in 1728. Meanwhile, as Russia received Orthodox Christianity from Byzantium, she inherited the Orthodox Calendar based on the Byzantine Era.
After the collapse of the Byzantine Empire in 1453, the era continued to be used by Russia, which witnessed millennialist movements in Moscow in AD 1492. It was only in AD 1700 that the Byzantine World Era in Russia was changed to the Julian Calendar by Peter the Great, it still forms the basis of traditional Orthodox calendars up to today. September AD 2000 began the year 7509 AM; the earliest extant Christian writings on the age of the world according to the Biblical chronology are by Theophilus, the sixth bishop of Antioch from the Apostles, in his apologetic work To Autolycus, by Julius Africanus in his Five Books of Chronology. Both of these early Christian writers, following the Septuagint version of the Old Testament, determined the age of the world to have been about 5,530 years at the birth of Christ. Ben Zion Wacholder points out that the writings of the Church Fathers on this subject are of vital significance, in that through the Christian chronographers a window to the earlier Hellenistic biblical chronographers is preserved: An immense intellectual effort was expended during the Hellenistic period by both Jews and pagans to date creation, the flood, building of the Temple...
In the course of their studies, men such as Tatian of Antioch, Clement of Alexandria, Hippolytus of Rome
The 15th century was the century which spans the Julian years 1401 to 1500. In Europe, the 15th century is seen as the bridge between the Late Middle Ages, the Early Renaissance, the Early modern period. Many technological and cultural developments of the 15th century can in retrospect be seen as heralding the "European miracle" of the following centuries. In religious history, the Roman Papacy was split in two parts in Europe for decades, until the Council of Constance; the division of the Catholic Church and the unrest associated with the Hussite movement would become factors in the rise of the Protestant Reformation in the following century. Constantinople, in what is today Turkey the capital of the Christian Byzantine Empire, falls to the emerging Muslim Ottoman Turks, marking the end of the tremendously influential Byzantine Empire and, for some historians, the end of the Middle Ages; the event forced Western Europeans to find a new trade route, adding further momentum to what was the beginning of the Age of Discovery, which would lead to the global mapping of the world.
Explorations by the Portuguese and Spanish led to European sightings of the Americas and the sea passage along Cape of Good Hope to India, in the last decade of the century. These expeditions ushered in the era of the Portuguese and Spanish colonial empires; the fall of Constantinople led to the migration of Greek scholars and texts to Italy, while Johannes Gutenberg's invention of the mechanical movable type began the Printing Press. These two events played key roles in the development of the Renaissance; the Spanish Reconquista leads to the final fall of the Emirate of Granada by the end of the century, ending over seven centuries of Muslim rule and returning Spain back to Christian rulers. The Hundred Years' War end with a decisive French victory over the English in the Battle of Castillon. Financial troubles in England following the conflict results in the Wars of the Roses, a series of dynastic wars for the throne of England; the conflicts end with the defeat of Richard III by Henry VII at the Battle of Bosworth Field, establishing the Tudor dynasty in the part of the century.
In Asia, under the rule of the Yongle Emperor, who built the Forbidden City and commanded Zheng He to explore the world overseas, the Ming Dynasty's territory reached its pinnacle. Tamerlane established a major empire in the Middle East and Central Asia, in order to revive the Mongol Empire. In Africa, the spread of Islam leads to the destruction of the Christian kingdoms of Nubia, by the end of the century leaving only Alodia; the vast Mali Empire teeters on the brink of collapse, under pressure from the rising Songhai Empire. In the Americas, both the Inca Empire and the Aztec Empire reach the peak of their influence. 1400s 1401: Dilawar Khan establishes the Malwa Sultanate in present-day central India 1402: Ottoman and Timurid Empires fight at the Battle of Ankara resulting in Timur's capture of Bayezid I. 1402: Sultanate of Malacca founded by Parameshwara. 1403: The Yongle Emperor moves the capital of China from Nanjing to Beijing. 1403: The settlement of the Canary Islands signals the beginning of the Spanish Empire.
1405–1433: Zheng He of China sails through the Indian Ocean to India and East Africa to spread China's influence and sovereignty. 1405: Paregreg war, Majapahit civil war of succession between Wikramawardhana against Wirabhumi. 1405–1407: The first voyage of Zheng He, a massive Ming dynasty naval expedition visited Java, Malacca, Aru and Lambri. 1410s 1410: The Battle of Grunwald is the decisive battle of the Polish–Lithuanian–Teutonic War leading to the downfall of the Teutonic Knights. 1410–1413: Foundation of St Andrews University in Scotland. 1414: Khizr Khan, deputised by Timur to be the governor of Multan, takes over Delhi founding the Sayyid dynasty. 1415: Henry the Navigator leads the conquest of Ceuta from the Moors marking the beginning of the Portuguese Empire. 1415: Battle of Agincourt fought between the Kingdom of England and France. 1415: Jan Hus is burned at the stake as a heretic at the Council of Constance.1420s 1420: Construction of the Chinese Forbidden City is completed in Beijing.
1420–1434: Hussite Wars in Bohemia. 1424: James I returns to Scotland after being held hostage under three Kings of England since 1406. 1424: Deva Raya II succeeds his father Veera Vijaya Bukka Raya as monarch of the Vijayanagara Empire. 1425: Catholic University of Leuven founded by Pope Martin V. 1429: Joan of Arc ends the Siege of Orléans and turns the tide of the Hundred Years' War. 1429: Queen Suhita succeeds Wikramawardhana as ruler of Majapahit.1430s 1431 January 9 – Pretrial investigations for Joan of Arc begin in Rouen, France under English occupation. March 3 – Pope Eugene IV succeeds Pope Martin V, to become the 207th pope. March 26 – The trial of Joan of Arc begins. May 30 – Nineteen-year-old Joan of Arc is burned at the stake. June 16 – the Teutonic Knights and Švitrigaila sign the Treaty of Christmemel, creating anti-Polish alliance September – Battle of Inverlochy: Donald Balloch defeats the Royalists. October 30 – Treaty of Medina del Campo, consolidating peace between Portugal and Castille.
December 16 – Henry VI of England is crowned King of France. 1438: Pachacuti founds the Inca Empire.1440s 1440: Eton College founded by Henry VI. 1440s: The Golden Horde breaks up into the Siberia Khanate, the Khanate of Kazan, the Astrakhan Khanate, the Crimean Khanate, the Great Horde. 1440–1469: Under Moctezuma I, the Aztecs become the dominant power in Mesoamerica. 1440: Oba Ewuare comes to power in the West African city of Benin, turns it into an empire. 1441: Jan van Eyck, Flemish painter, dies. 1441: Portuguese navigators cruise West
Kali Yuga in Hinduism is the last of the four stages the world goes through as part of a'cycle of yugas' described in the Sanskrit scriptures. The other ages are called Satya Yuga, Treta Yuga, Dvapara Yuga. Kali Yuga is associated with the demon Kali; the "Kali" of Kali Yuga means "strife", "discord", "quarrel" or "contention". According to Puranic sources, Krishna's departure marks the end of Dvapara Yuga and the start of Kali Yuga, dated to 17/18 February 3102 BCE. According to the Surya Siddhanta, Kali Yuga began at midnight on 18 February 3102 BCE; this is considered the date on which Lord Krishna left the earth to return to Vaikuntha. This information is placed at the temple of the place of this incident. According to the astronomer and mathematician Aryabhatta the Kali Yuga started in 3102 BCE, he finished his book "Aryabhattiya" in 499 CE, in which he gives the exact year of the beginning of Kali Yuga. He writes that he wrote the book in the "year 3600 of the Kali Age" at the age of 23; as it was the 3600th year of the Kali Age when he was 23 years old, given that Aryabhatta was born in 476 CE, the beginning of the Kali Yuga would come to 3102 BCE.
According to KD Abhyankar, the starting point of Kali Yuga is an rare planetary alignment, depicted in the Mohenjo-Daro seals. Going by this alignment the year 3102 BCE is off; the actual date for this alignment is 7 February of 3104 BCE. There is sufficient proof to believe that Vrdhha Garga knew of precession at least by 500 BCE. Garga had calculated the rate of precession to within 30 % of; the common belief until Swami Sri Yukteswar Giri had analyzed the dating of the Yuga cycles was that the Kali Yuga would last for 432,000 years after the end of the Dwapara Yuga. This originated during the puranic times when the famous astronomer Aryabhatta recalculated the timeline by artificially inflating the traditional 12,000 year figure with a multiplication of 360, represented as the number of "human years" that make up a single "divine year"; this was a purposeful miscalculation due to conflicts with one of the preeminent astronomer of the time Brahmagupta. However, both the Mahabharata and the Manu Smriti have the original value of 12,000 years for one half of the Yuga cycle.
Contemporary analysis of historical data from the last 11 millennia matches with the indigenous Saptarishi Calendar. The length of the transitional periods between each Yuga is unclear, can only be estimated based on historical data of past cataclysmic events. Using a 300 year period for transitions, Kali Yuga has either ended in the past 100 to 200 years, or is to end soon sometime in the next 100 years. Other authors, such as the revered Hindu guru Swami Sri Yukteswar in his book The Holy Science, as well as the influential Yogi Paramhansa Yogananda, believe that the Kali Yuga has ended, that we are now in an ascending Dvapara Yuga; this calculation is supported by modern day spiritual masters such as Sadhguru Jaggi Vasudev. Hindus believe that human civilization degenerates spiritually during the Kali Yuga, referred to as the Dark Age because in it people are as far away as possible from God. Hinduism symbolically represents morality as an Indian bull. Common attributes and consequences are spiritual bankruptcy, mindless hedonism, breakdown of all social structure and materialism, unrestricted egotism and maladies of mind and body.
In Satya Yuga, the first stage of development, the bull has four legs, but in each age morality is reduced by one quarter. By the age of Kali, morality is reduced to only a quarter of that of the golden age, so that the bull of Dharma has only one leg; the Mahabharata War and the decimation of Kauravas thus happened at the "Yuga-Sandhi", the point of transition from one yuga to another. The scriptures mention Sage Narada to have momentarily intercepted the demon Kali on his way to the Earth when Duryodhana was about to be born in order to make him an embodiment of arishadvargas and adharma in preparation of the era of decay in values and the consequent havoc. A discourse by Markandeya in the Mahabharata identifies some of the attributes of Kali Yuga. In relation to rulers, it lists: Rulers will become unreasonable: they will levy taxes unfairly. Rulers will no longer see it as their duty to promote spirituality, or to protect their subjects: they will become a danger to the world. People will start seeking countries where wheat and barley form the staple food source.
"At the end of Kali-yuga, when there exist no topics on the subject of God at the residences of so-called saints and respectable gentlemen of the three higher varnas and when nothing is known of the techniques of sacrifice by word, at that time the Lord will appear as the supreme chastiser." (Srimad-Bhagavatam With regard to human relationships, Markandeya's discourse says: Avarice and wrath will be common. Humans will display animosity towards each other. Ignorance of dharma will occur. People will see nothing wrong in that. Lust will be viewed as acceptable and sexual intercourse will be seen as the central requirement of life. Sin will increase exponentially, while virtue will cease to flourish. People will become addicted to intoxicating drugs. Gurus will no longer be respected and their students will attempt
Indian national calendar
The Indian national calendar, sometimes called the Shalivahana Shaka calendar. It is used, alongside the Gregorian calendar, by The Gazette of India, in news broadcasts by All India Radio and in calendars and communications issued by the Government of India; the Saka calendar is used in Java and Bali among Indonesian Hindus. Nyepi, the "Day of Silence", is a celebration of the Saka new year in Bali. Nepal's Nepal Sambat evolved from the Saka calendar. Prior to colonization, the Philippines used to apply the Saka calendar as well as suggested by the Laguna Copperplate Inscription; the term may ambiguously refer to the Hindu calendar. The historic Shalivahana era calendar is still used, it has years. The calendar months follow the signs of the tropical zodiac rather than the sidereal zodiac used with the Hindu calendar. Chaitra has 30 days and starts on March 22, except in leap years, when it has 31 days and starts on March 21; the months in the first half of the year all have 31 days, to take into account the slower movement of the sun across the ecliptic at this time.
The names of the months are derived from older, Hindu lunisolar calendars, so variations in spelling exist, there is a possible source of confusion as to what calendar a date belongs to. Years are counted in the Saka era. To determine leap years, add 78 to the Saka year – if the result is a leap year in the Gregorian calendar the Saka year is a leap year as well, its structure is just like the Persian calendar. Senior Indian Astrophysicist Meghnad Saha was the head of the Calendar Reform Committee under the aegis of the Council of Scientific and Industrial Research. Other members of the Committee were: A. C. Banerjee, K. K. Daftari, J. S. Karandikar, Gorakh Prasad, R. V. Vaidya and N. C. Lahiri, it was Saha's effort. The task before the Committee was to prepare an accurate calendar based on scientific study, which could be adopted uniformly throughout India, it was a mammoth task. The Committee had to undertake a detailed study of different calendars prevalent in different parts of the country. There were thirty different calendars.
The task was further complicated by the fact that religion and local sentiments were integral to those calendars. India's first prime minister, Jawaharlal Nehru, in his preface to the Report of the Committee, published in 1955, wrote: “They represent past political divisions in the country.... Now that we have attained Independence, it is desirable that there should be a certain uniformity in the calendar for our civic and other purposes, this should be done on a scientific approach to this problem.” Usage started at 1 Chaitra 1879, Saka Era, or 22 March 1957. Report of the Calendar Reform Committee – online link. Mapping Time: The Calendar and its History by E. G. Richards, 1998, pp. 184–185. Calendars and their History Indian Calendars Positional astronomy in India Indian National Calendar abstract
Republic of China (1912–1949)
The Republic of China controlled the Chinese mainland between 1912 and 1949. It was established in January 1912 after the Xinhai Revolution, which overthrew the Qing dynasty, the last imperial dynasty of China, its government moved to Taipei in December 1949 due to the Kuomintang's defeat in the Chinese Civil War. The Republic's first president, Sun Yat-sen, served only before handing over the position to Yuan Shikai, leader of the Beiyang Army, his party led by Song Jiaoren, won the parliamentary election held in December 1912. Song Jiaoren was assassinated shortly after and the Beiyang Army led by Yuan Shikai maintained full control of the Beiyang government. Between late 1915 and early 1916, Yuan Shikai tried to reinstate the monarchy before abdicating due to popular unrest. After Yuan Shikai's death in 1916, members of cliques in the Beiyang Army claimed their autonomy and clashed with each other. During this period, the authority of the Beiyang government was weakened by a restoration of the Qing dynasty.
In 1921, Sun Yat-sen's Kuomintang established a rival government in Canton City, Canton Province, together with the fledgling Communist Party of China. The economy of North China, overtaxed to support warlord adventurism, collapsed between 1927 and 1928. General Chiang Kai-shek, who became KMT leader after Sun Yat-sen's death, started the Northern Expedition military campaign in 1926 to overthrow the Beiyang government, completed in 1928. In April 1927, Chiang established a nationalist government in Nanking, massacred communists in Shanghai, which forced the CPC into armed rebellion, marking the beginning of the Chinese Civil War. There were industrialization and modernization, but conflict between the Nationalist government in Nanking, the CPC, remnant warlords, the Empire of Japan. Nation-building took a backseat to the Second Sino-Japanese War when the Imperial Japanese Army launched an offensive against China in 1937 that turned into a full-scale invasion. After the surrender of Japan at the end of World War II in 1945, the Chinese Civil War resumed in 1946 between the KMT and CPC, with both sides receiving foreign assistance due to the Cold War from the USA and USSR, respectively.
During this period, the 1946 Constitution of the Republic of China replaced the 1928 Organic Law as the Republic's fundamental law. Near the end of the Chinese Civil War in 1949, the Chinese Communist Party established the People's Republic of China, overthrowing the nationalist government on the Chinese mainland; the Government of the Republic of China moved from Nanking to Taipei in 1949, controlling only the Taiwan area after 1949. The official name of the state in the mainland was the "Republic of China". Shortly after the ROC's establishment in 1912, while it was still located on the Chinese mainland, the government used the short form "China" to refer to itself, which derives from zhōng and guó, a term which developed under the Zhou dynasty in reference to its royal demesne, the name was applied to the area around Luoyi during the Eastern Zhou and to China's Central Plain before being used as an occasional synonym for the state during the Qing era; the ROC used alternate names throughout its existence were Republican China or Republican Era, as well as the Beiyang government, the Nationalist government.
A republic was formally established on 1 January 1912 following the Xinhai Revolution, which itself began with the Wuchang Uprising on 10 October 1911 overthrowing the Qing dynasty and ending over two thousand years of imperial rule in China. From its founding until 1949 it was based on mainland China. Central authority waxed and waned in response to warlordism, Japanese invasion, a full-scale civil war, with central authority strongest during the Nanjing Decade, when most of China came under the control of the Kuomintang under an authoritarian one-party military dictatorship. At the end of World War II in 1945, the Empire of Japan surrendered control of Taiwan and its island groups to the Allies, Taiwan was placed under the Republic of China's administrative control; the communist takeover of mainland China in the Chinese Civil War in 1949 left the ruling Kuomintang with control over only Taiwan, Kinmen and other minor islands. With the 1949 loss of mainland China in the civil war, the ROC government retreated to Taiwan and the KMT declared Taipei the provisional capital.
The Communist Party of China took over all of mainland China and founded the People's Republic of China in Beijing. In 1912, after over two thousand years of imperial rule, a republic was established to replace the monarchy; the Qing dynasty that preceded the republic experienced a century of instability throughout the 19th century, suffered from both internal rebellion and foreign imperialism. The ongoing instability led to the outburst of Boxer Rebellion in 1900, whose attacks on foreigners led to the invasion by the Eight Nation Alliance. China signed the Boxer Protocol and paid a large indemnity to the foreign powers: 450 million taels of fine silver. A program of institutional reform proved too late. Only the lack of an alternative regime prolonged its existence until 1912; the establishment of the Chinese Republic developed out of the Wuchang Uprising against the Qing government on 10 October 1911. That date is now celebrated annually as the ROC's national day known as the "Double Ten Day".
On 29 December 1911, Sun Yat-sen was elected president b
Balinese saka calendar
The Balinese saka calendar is one of two calendars used on the Indonesian island of Bali. Unlike the 210-day pawukon calendar, it is based on the phases of the Moon, is the same length as the Gregorian year. Based on a lunar calendar, the saka year comprises sasih, of 30 days each. However, because the lunar cycle is shorter than 30 days, the lunar year has a length of 354 or 355 days, the calendar is adjusted to prevent it losing synchronization with the lunar or solar cycles; the months are adjusted by allocating two lunar days to one solar day every 9 weeks. This day is called ngunalatri, Sanskrit for "minus one night". To stop the Saka from lagging behind the Gregorian calendar – as happens with the Islamic calendar, an extra month, known as an intercalary month, is added after the 11th month, or after the 12th month; the length of these months is calculated according to the normal 63-day cycle. An intercalary month is added whenever necessary to prevent the final day of the 7th month, known as Tilem Kapitu, from falling in the Gregorian month of December.
The names the twelve months are taken from a mixture of Old Balinese and Sanskrit words for 1 to 12, are as follows: Kasa Karo Katiga Kapat Kalima Kanem Kapitu Kawalu Kasanga Kadasa Jyestha SadhaEach month begins the day after a new moon and has 15 days of waxing moon until the full moon 15 days of waning, ending on the new moon. Both sets of days are numbered 1 to 15; the first day of the year is the day after the first new moon in March. Note, that Nyepi falls on the first day of Kadasa, that the years of the Saka era are counted from that date; the calendar is 78 years behind the Gregorian calendar, is calculated from the beginning of the Saka Era in India. It is used alongside the 210-day Balinese pawukon calendar, Balinese festivals can be calculated according to either year; the Indian saka calendar was used for royal decrees as early as the ninth century CE. The same calendar was used in Java until Sultan Agung replaced it with the Javanese calendar in 1633; the Balinese Hindu festival of Nyepi, the day of silence, marks the start of the Saka year.
Tilem Kepitu, the last day of the 7th month, is known as Siva Ratri, is a night dedicated to the god Shiva. Devotees stay up all meditate. There are another 24 ceremonial days in the Saka year celebrated at Purnama. Eiseman, Fred B. Jr, Bali: Sekalia and Niskala Volume I: Essays on Religion and Art pp 182–185, Periplus Editions, 1989 ISBN 0-945971-03-6 Haer, Debbie Guthrie. ISBN 981 3018 496 Hobart, Angela. ISBN 0 631 17687 X Ricklefs, M. C.
The traditional China calendar, or Former Calendar, Traditional Calendar or Lunar Calendar, is a lunisolar calendar which reckons years and days according to astronomical phenomena. It is defined by GB/T 33661-2017, "Calculation and promulgation of the Chinese calendar", issued by the Standardisation Administration of China on 12 May 2017. Although modern day China uses the Gregorian calendar, the traditional Chinese calendar governs holidays in China and in overseas Chinese communities, it lists the dates of traditional Chinese holidays and guides people in selecting auspicious days for weddings, moving, or starting a business. Like Chinese characters, variants of this calendar are used in different parts of the Chinese cultural sphere. Korea and the Ryukyu Islands adopted the calendar, it evolved into Korean and Ryukyuan calendars; the main difference from the traditional Chinese calendar is the use of different meridians, which leads to some astronomical events—and calendar events based on them—falling on different dates.
The traditional Japanese calendar derived from the Chinese calendar, but its official use in Japan was abolished in 1873 as part of reforms after the Meiji Restoration. Calendars in Mongolia and Tibet have absorbed elements of the traditional Chinese calendar, but are not direct descendants of it. Days begin and end at midnight, months begin on the day of the new moon. Years begin on the second new moon after the winter solstice. Solar terms govern the end of each month. Written versions in ancient China included stems and branches of the year and the names of each month, including leap months as needed. Characters indicated whether a month was short; the traditional Chinese calendar was developed between 771 and 476 BC, during the Spring and Autumn period of the Eastern Zhou dynasty. Before the Zhou dynasty, solar calendars were used. One version of the solar calendar is the five-elements calendar. A 365-day year was divided into five phases of 73 days, with each phase corresponding to a Day 1 Wu Xing element.
A phase began followed by six 12-day weeks. Each phase consisted of two three-week months. Years began followed by a bǐngzǐ day and a 72-day fire phase. Other days were tracked using the Yellow River Map. Another version is a four-quarters calendar. Weeks were ten days long, with one month consisting of three weeks. A year had 12 months, with a ten-day week 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. A third version is the balanced calendar. A year was 365.25 days, a month was 29.5 days. After every 16th month, a half-month was intercalated. According to oracle bone records, the Shang dynasty calendar was a balanced calendar with 12 to 14 months in a year; the first lunisolar calendar was the Zhou calendar, introduced under the Zhou dynasty. This calendar set the beginning of the year at the day of the new moon before the winter solstice, it set the shàngyuán as the winter solstice of a dīngsì year, making the year it was introduced around 2,758,130.
Several competing lunisolar calendars were introduced by states fighting Zhou control during the Warring States period. The state of Lu issued its own Lu calendar. Jin issued the Xia calendar in AD 102, with a year beginning on the day of the new moon nearest the March equinox. Qin issued the Zhuanxu calendar, with a year beginning on the day of the new moon nearest the winter solstice. Song's Yin calendar began its year on the day of the new moon after the winter solstice; these calendars are known as the six ancient calendars, or quarter-remainder calendars, since all calculate a year as 365 1⁄4 days long. Months begin on the day of the new moon, a year has 12 or 13 months. Intercalary months are added to the end of the year; the Qiang and Dai calendars are modern versions of the Zhuanxu calendar, used by mountain peoples. After Qin Shi Huang unified China under the Qin dynasty in 221 BC, the Qin calendar was introduced, it followed most of the rules governing the Zhuanxu calendar, but the month order was that of the Xia calendar.
The intercalary month, known as the second Jiǔyuè, was placed at the end of the year. The Qin calendar was used into the Han dynasty. Emperor Wu of Han r. 141 – 87 BC introduced reforms halfway through his reign. His Taichu Calendar defined a solar year as 365 385⁄1539 days, the lunar month was 29 43⁄81 days; this calendar introduced the 24 solar terms. 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, the second was a mid-climate. Months were named for the mid-climat