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
The Dragon is the fifth of the 12-year cycle of animals which appear in the Chinese zodiac related to the Chinese calendar. The Year of the Dragon is associated with pronounced chen, it has been proposed by one academic researcher that the Earthly Branch character may have been associated with scorpions. In the Buddhist calendar used in Thailand, Laos and Sri Lanka, the Dragon is replaced by the nāga. In the Gurung zodiac, the Dragon is replaced by the eagle. People born within these date ranges can be said to have been born in the "Year of the Dragon", while bearing the following elemental sign: There are marked spikes in the birth rates of countries that use the Chinese zodiac or places with substantial Overseas Chinese populations during the year of the Dragon, because such "Dragon babies" are considered to be lucky and have desirable characteristics that lead to better life outcomes; the recent phenomenon of planning a child’s birth in the Dragon year has led to hospital overcapacity issues and an uptick in infant mortality rates toward the end of these years due to strained neonatal resources.
Among the 12 animal signs, the Monkey has the most tacit understanding with the Dragon people. The cunning Rat can be a good partner with the Dragon to make something big; the Dragon people can live with the Snake, for the Snake can prevent the Dragon from behaving outrageously. People under the signs of the Rooster, Rabbit, Goat and Horse like to be friends with the Dragon, as they admire the Dragon's beautiful bearing and strength. Two Dragons can get along well with each other. However, the relationship between the Dragon and the Ox people is tense, because both of them are majestic; the people whom the Dragon feels headaches with the most are the Dog people. They feel uncomfortable due to the Dog's close guard
The Islamic, Muslim, or Hijri calendar is a lunar calendar consisting of 12 lunar months in a year of 354 or 355 days. It is used to determine the proper days of Islamic holidays and rituals, such as the annual period of fasting and the proper time for the pilgrimage to Mecca; the civil calendar of all countries where the religion is predominantly Muslim is the Gregorian calendar. Notable exceptions to this rule are Afghanistan, which use the Solar Hijri calendar. Rents and similar regular commitments are paid by the civil calendar; the Islamic calendar employs the Hijri era whose epoch was established as the Islamic New Year of 622 AD/CE. During that year and his followers migrated from Mecca to Yathrib and established the first Muslim community, an event commemorated as the Hijra. In the West, dates in this era are denoted AH in parallel with the Christian and Jewish eras. In Muslim countries, it is sometimes denoted as H from its Arabic form. In English, years prior to the Hijra are reckoned as BH.
The current Islamic year is 1440 AH. In the Gregorian calendar, 1440 AH runs from 11 September 2018 to 30 August 2019. For central Arabia Mecca, there is a lack of epigraphical evidence but details are found in the writings of Muslim authors of the Abbasid era. Inscriptions of the ancient South Arabian calendars reveal the use of a number of local calendars. At least some of these South Arabian calendars followed the lunisolar system. Both al-Biruni and al-Mas'udi suggest that the ancient Arabs used the same month names as the Muslims, though they record other month names used by the pre-Islamic Arabs; the Islamic tradition is unanimous in stating that Arabs of Tihamah and Najd distinguished between two types of months and forbidden months. The forbidden months were four months during which fighting is forbidden, listed as Rajab and the three months around the pilgrimage season, Dhu al-Qa‘dah, Dhu al-Hijjah, Muharram. Information about the forbidden months is found in the writings of Procopius, where he describes an armistice with the Eastern Arabs of the Lakhmid al-Mundhir which happened in the summer of 541 AD/CE.
However, Muslim historians do not link these months to a particular season. The Qur'an links the four forbidden months with Nasī’, a word that means "postponement". According to Muslim tradition, the decision of postponement was administered by the tribe of Kinanah, by a man known as the al-Qalammas of Kinanah and his descendants. Different interpretations of the concept of Nasī’ have been proposed; some scholars, both Muslim and Western, maintain that the pre-Islamic calendar used in central Arabia was a purely lunar calendar similar to the modern Islamic calendar. According to this view, Nasī’ is related to the pre-Islamic practices of the Meccan Arabs, where they would alter the distribution of the forbidden months within a given year without implying a calendar manipulation; this interpretation is supported by Arab historians and lexicographers, like Ibn Hisham, Ibn Manzur, the corpus of Qur'anic exegesis. This is corroborated by an early Sabaic inscription, where a religious ritual was "postponed" due to war.
According to the context of this inscription, the verb ns'’ has nothing to do with intercalation, but only with moving religious events within the calendar itself. The similarity between the religious concept of this ancient inscription and the Qur'an suggests that non-calendaring postponement is the Qur'anic meaning of Nasī’; the Encyclopaedia of Islam concludes "The Arabic system of can only have been intended to move the Hajj and the fairs associated with it in the vicinity of Mecca to a suitable season of the year. It was not intended to establish a fixed calendar to be observed." The term "fixed calendar" is understood to refer to the non-intercalated calendar. Others concur that it was a lunar calendar, but suggest that about 200 years before the Hijra it was transformed into a lunisolar calendar containing an intercalary month added from time to time to keep the pilgrimage within the season of the year when merchandise was most abundant; this interpretation was first proposed by the medieval Muslim astrologer and astronomer Abu Ma'shar al-Balkhi, by al-Biruni, al-Mas'udi, some western scholars.
This interpretation considers Nasī’ to be a synonym to the Arabic word for "intercalation". The Arabs, according to one explanation mentioned by Abu Ma'shar, learned of this type of intercalation from the Jews; the Jewish Nasi was the official. Some sources say that the Arabs followed the Jewish practice and intercalated seven months over nineteen years, or else that they intercalated nine months over 24 years. Postponement of one ritual in a particular circumstance does not imply alteration of the sequence of months, scholars agree that this did not happen. Al-Biruni says this did not happen, the festivals were kept within their season by intercalation every second or third year of a month between Dhu al-Hijjah and Muharram, he says that, in terms of the fixed calendar, not introduced until 10 AH, the first intercalation was, for example, of a month between Dhu al-Hijjah and Muharram, the second of a month between Muharram and Safar, the third of a month between Safar and Rabi'I, so on. The intercalations were arranged.
The notice of interca
Vikram Samvat. It uses solar sidereal years; the Vikram Samvat is notable because many medieval era inscriptions use it. It is said to be named after the legendary king Vikramaditya, but the term "Vikrama Samvat" does not appear in the historical records before the 9th century, rather the same calendaring system is found by other names such as Krita and Malava. In the colonial era scholarship, the era was believed to be based on the commemoration of King Vikramaditya expelling the Sakas from Ujjain; however epigraphical evidence and scholarship suggest that this theory has no historical basis and likely was an error. Starting in the 9th century and thereafter, epigraphical artwork uses Vikrama-Samvat, suggesting that sometime around the 9th-century, the Hindu calendar era, in use became popular as Vikram Samvat, while Buddhist and Jain epigraphy continued to use an era based on the Buddha or the Mahavira. According to popular tradition, the legendary king Vikramaditya of Ujjain established the Vikrama Samvat era after defeating the Śakas.
Kalakacharya Kathanaka by the Jain sage Mahesarasuri gives the following account: Gandharvasena, the then-powerful king of Ujjain, abducted a nun called Sarasvati, the sister of the monk. The enraged monk sought the help of the Śaka ruler King Sahi in Sistan. Despite heavy odds but aided by miracles, the Śaka king defeated Gandharvasena and made him a captive. Sarasvati was repatriated; the defeated king retired to the forest. His son, being brought up in the forest, had to rule from Pratishthana. On, Vikramaditya invaded Ujjain and drove away from the Śakas. To commemorate this event, he started a new era called the "Vikrama era"; the Ujjain calendar started around 58–56 BCE, the subsequent Shaka era calendar was started in 78 CE at Pratishthana. The association of the era beginning in 57 BCE with Vikramaditya is not found in any source before the 9th century CE; the earlier sources call this era by various names, including Kṛṭa, the era of the Malava tribe, or Samvat. The earliest known inscription that calls the era "Vikrama" is from 842 CE.
This inscription of Chauhana ruler Chandamahasena was found at Dholpur, is dated Vikrama Samvat 898, Vaishakha Shukla 2, Chanda. The earliest known inscription that associates this era with a king called Vikramaditya is dated 971 CE; the earliest literary work that connects the era to Vikramaditya is Subhashita-Ratna-Sandoha by the Jain author Amitagati. For this reason, multiple authors believe that the Vikram Samvat was not started by Vikramaditya, who might be a purely legendary king or the title adopted by a king who renamed the era after himself. V. A. Smith and D. R. Bhandarkar believed that Chandragupta II adopted the title Vikramaditya, changed the name of the era to "Vikrama Samvat". According to Rudolf Hoernlé, the king responsible for this change was Yashodharman: Hoernlé believed that he conquered Kashmir, is the same person as the "Harsha Vikramaditya" mentioned in Kalhana's Rajatarangini. Earlier, some scholars believed that the Vikrama Samavat corresponded to the Azes era of the Indo-Scythian king King Azes.
However, this was disputed by Robert Bracey following the discovery of an inscription of Vijayamitra, dated in two eras. The theory seems to be now discredited by Falk and Bennett, who place the inception of the Azes era in 47–46 BCE; the traditional New Year of Vikram Samvat is one of the many festivals of Nepal, marked by parties, family gatherings, the exchange of good wishes, participation in rituals to ensure good fortune in the coming year. It occurs in mid-April each year, coincides with the traditional new year in Assam, Burma, Kerala, Manipur, Punjab, Sri Lanka, Tamil Nadu and Thailand. In addition to Nepal, the Vikram Samvat calendar is recognized in North and East India, in Gujarat among Hindus. Hindu religious festivals are based on a Luni-Solar calendar, not Solar calendar, based on Vikram Samvat. In North India, the new year in Vikram Samvat starts from the first day of Chaitra Skukla paksha. In Buddhist communities, the month of Baishakh is associated with Buddha's Birthday, it commemorates the birth and passing of Gautama Buddha on the first full moon day in May, except in a leap year when the festival is held in June.
Although this festival is not held on the same day as Pahela Baishakh, the holidays fall in the same month of the Bengali and Theravada Buddhist calendars, are related through the spread of Hinduism and Buddhism in the Indian subcontinent. In Gujarat, the day after Diwali is celebrated as the first day of the Vikram Samvat calendar, the first day of the month Kartik; the Vikrami era is an ancient calendar and has been used by Hindus and Sikhs. It is one of the several regional Hindu calendars that have been in use on the Indian subcontinent, it is based on twelve synodical lunar months and 365 solar days; the lunar new year starts on the new moon in the month of Chaitra. This day, known as Chaitra Sukhladi, is a restricted holiday in India; the Vikrami Samvat has been in use in the Indian subcontinent since ancient times, remains in use by the Hindus in north, w
The 3rd century was the period from 201 to 300 A. D. or C. E. In this century, the Roman Empire saw a crisis, starting with the assassination of the Roman Emperor Severus Alexander in 235, plunging the empire into a period of economic troubles, barbarian incursions, political upheavals, civil wars, the split of the Roman Empire through the Gallic Empire in the west and the Palmyrene Empire in the east, which all together threatened to destroy the Roman Empire in its entirety, but the reconquests of the seceded territories by Emperor Aurelian and the stabilization period under Emperor Diocletian due to the administrative strengthening of the empire caused an end to the crisis by 284; this crisis would mark the beginning of Late Antiquity. In Persia, the Parthian Empire was succeeded by the Sassanid Empire in 224 after Ardashir I defeated and killed Artabanus V during the Battle of Hormozdgan; the Sassanids went on to subjugate many of the western portions of the declining Kushan Empire. In China, the chaos, raging since 189 would continue to persist with the decisive defeat of Cao Cao at the Battle of Red Cliffs in 208, which would end the hopes of unification and lead to the tripartite division of China into three main empires.
In India, the Gupta Empire was on the rise towards the end of the century. Korea was ruled by the Three Kingdoms of Korea. Japan entered the Kofun period; the Xiongnu formed the Tiefu state under Liu Qubei. The Southeast Asian mainland was dominated by Funan. At about this time in Sub-Saharan Africa, the Bantu expansion reached Southern Africa. In Pre-Columbian America, the Adena culture of the Ohio River valley declined in favor of the Hopewell culture; the Maya civilization entered its Classic Era. After the death of Commodus in the late previous century the Roman Empire was plunged into a civil war; when the dust settled, Septimius Severus emerged as emperor. Unlike previous emperors, he used the army to back his authority, paid them well to do so; the regime he created is known as the Military Monarchy as a result. The system fell apart in the 230s, giving way to a fifty-year period known as the Military Anarchy or the Crisis of the Third Century, following the assassination of the 28-year-old emperor Severus Alexander, where no fewer than twenty emperors held the reins of power, most for only a few months.
The majority of these men were assassinated, or killed in battle, the empire collapsed under the weight of the political upheaval, as well as the growing Persian threat in the east. Under its new Sassanid rulers, Persia had grown into a rival superpower, the Romans would have to make drastic reforms in order to better prepare their state for a confrontation; these reforms were realized late in the century under the reign of Diocletian, one of them being to divide the empire into an eastern and western half, have a separate ruler for each. Early 3rd century – Burial in catacombs becomes common place. 208: the Chinese naval Battle of Red Cliffs occurs. 211 – 217: Caracalla, Roman Emperor. 212: Constitutio Antoniniana grants citizenship to all free Roman men. 212 – 217: Baths of Caracalla. 220: The Han Dynasty comes to an end with establishment of the Three Kingdoms in ancient China. 220 – 280: The Three Kingdoms period. 222 – 235: Alexander Severus, Roman Emperor. 224: Ardashir I of the Sassanid dynasty conquers the Parthian empire at the Battle of Hormozdgān.
230 – 232: Sassanid dynasty of Persia launches a war to reconquer lost lands in the Roman east. 234: Zhuge Liang dies of illness at the standoff of Wuzhang Plains. 235 – 284: Crisis of the Third Century shakes Roman Empire. 241: The Kingdom of Araba dissolved after the Fall of Hatra to Persia 244: Battle of Xingshi in China. 250 – 538: Kofun era, the first part of the Kofun period in Japan. 258: Valerian's massacre of Christians. 260: Roman Emperor Valerian I is taken captive by Shapur I of Persia. 263: Cao Wei conquers the Shu Han Kingdom. 266: The Jin Dynasty is founded after the overthrow of the Cao Wei Dynasty by Sima Yan. 280: The Jin Dynasty reunites China under one empire after the conquest of Eastern Wu. 284 – 305: Diocletian, Roman Emperor. 291 – 306: The War of the Eight Princes, a civil war by the Sima Clan in China. Sarnath becomes a center of Buddhist arts in India. Diffusion of maize as a food crop from Mexico into North America begins; the Kingdom of Funan reaches its zenith. The Goths move from Gothiscandza to Ukraine.
Menorahs and Ark of the Covenant, wall painting in a Jewish catacomb, Villa Torlonia, are made. The Coptic period begins. Siddhartha in the Palace, detail of a relief from Nagarjunakonda, Andhra Pradesh, India, is made. Andhra period; the artwork is now kept at New Delhi. Jonah Swallowed and Jonah Cast Up, two statuettes of a group from the eastern Mediterranean Asia Minor, are made. Now kept at The Cleveland Museum of Art; the Magerius Mosaic is made. Late 3rd century-early 4th century – Good Shepherd and Story of Jonah, painted ceiling of the Catacombs of Marcellinus and Peter in Rome, is made. Ardashir I, founder of the Sasanid Empire Artabanus V, last ruler of the Parthian Empire Aurelian, Roman emperor Clement of Alexandria, Christian head of Catechetical School of Alexandria Cao Ca
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
The Buddhist calendar is a set of lunisolar calendars used in mainland Southeast Asian countries of Cambodia, Laos and Thailand as well as in Sri Lanka and Chinese populations of Malaysia and Singapore for religious or official occasions. While the calendars share a common lineage, they have minor but important variations such as intercalation schedules, month names and numbering, use of cycles, etc. In Thailand, the name Buddhist Era is a year numbering system shared by the traditional Thai lunisolar calendar and by the Thai solar calendar; the Southeast Asian lunisolar calendars are based on an older version of the Hindu calendar, which uses the sidereal year as the solar year. One major difference is that the Southeast Asian systems, unlike their Indian cousins, do not use apparent reckoning to stay in sync with the sidereal year. Instead, they employ their versions of the Metonic cycle. However, since the Metonic cycle is not accurate for sidereal years, the Southeast Asian calendar is drifting out of sync with the sidereal one day every 100 years.
Yet no coordinated structural reforms of the lunisolar calendar have been undertaken. Today, the traditional Buddhist lunisolar calendar is used for Theravada Buddhist festivals, no longer has the official calendar status anywhere; the Thai Buddhist Era, a renumbered Gregorian calendar, is the official calendar in Thailand. The calculation methodology of the current versions of Southeast Asian Buddhist calendars is based on that of the Burmese calendar, in use in various Southeast Asian kingdoms down to the 19th century under the names of Chula Sakarat and Jolak Sakaraj; the Burmese calendar in turn was based on the "original" Surya Siddhanta system of ancient India. One key difference with Indian systems is that the Burmese system has followed a variation of the Metonic cycle, it is unclear from where, how the Metonic system was introduced. The Burmese system, indeed the Southeast Asian systems, thus use a "strange" combination of sidereal years from Indian calendar in combination with the Metonic cycle better for tropical years.
In all Theravada traditions, the calendar's epochal year 0 date was the day in which the Buddha attained parinibbāna. However, not all traditions agree on when it took place. In Burmese Buddhist tradition, it was 13 May 544 BCE, but in Thailand, it was 11 March 545 BCE, the date which the current Thai lunisolar and solar calendars use as the epochal date. Yet, the Thai calendars for some reason have fixed the difference between their Buddhist Era numbering and the Christian/Common Era numbering at 543, which points to an epochal year of 544 BCE, not 545 BCE. In Myanmar, the difference between BE and CE can be 543 or 544 for CE dates, 544 or 543 for BCE dates, depending on the month of the Buddhist Era. In Sri Lanka, the difference between BE and CE is 544; the calendar recognizes two types of months: sidereal month. The Synodic months are used to compose the years while the 27 lunar sidereal days, alongside the 12 signs of the zodiac, are used for astrological calculations; the days of the month are counted in two halves and waning.
The 15th of the waxing is the civil full moon day. The civil new moon day is the last day of the month; because of the inaccuracy of the calendrical calculation systems, the mean and real New Moons coincide. The mean New Moon precedes the real New Moon; as the Synodic lunar month is 29.5 days, the calendar uses alternating months of 29 and 30 days. Various regional versions of Chula Sakarat/Burmese calendar existed across various regions of mainland Southeast Asia. Unlike Burmese systems, Lan Na, Lan Xang and Sukhothai systems refer to the months by numbers, not by names; this means reading ancient texts and inscriptions in Thailand requires constant vigilance, not just in making sure one is operating for the correct region, but for variations within regions itself when incursions cause a variation in practice. However, Cambodian month system, which begins with Margasirsa as the first month, demonstrated by the names and numbers; the Buddhist calendar is a lunisolar calendar in which the months are based on lunar months and years are based on solar years.
One of its primary objectives is to synchronize the lunar part with the solar part. The lunar months twelve of them, consist alternately of 29 days and 30 days, such that a normal lunar year will contain 354 days, as opposed to the solar year of ~365.25 days. Therefore, some form of addition to the lunar year is necessary; the overall basis for it is provided by cycles of 57 years. Eleven extra days are inserted in every 57 years, seven extra months of 30 days are inserted in every 19 years; this provides 20819 complete days to both calendars. This 57-year cycle would provide a mean year of about 365.2456 days and a mean month of about 29.530496 days, if not corrected. As such, the calendar adds an intercalary month in leap years and sometimes an intercalary day in great leap years; the intercalary month not only corrects the length of the year but corrects the accumulating error of the month to extent of half a day. The average length of the month is further corrected by adding a day to Nayon