The Hebrew or Jewish calendar is a lunisolar calendar used today predominantly for Jewish religious observances. It determines the dates for Jewish holidays and the appropriate public reading of Torah portions and daily Psalm readings, among many ceremonial uses. In Israel, it is used for religious purposes, provides a time frame for agriculture and is an official calendar for civil purposes, although the latter usage has been declining in favor of the Gregorian calendar; the present Hebrew calendar is the product including a Babylonian influence. Until the Tannaitic period, the calendar employed a new crescent moon, with an additional month added every two or three years to correct for the difference between twelve lunar months and the solar year; the year in which it was added was based on observation of natural agriculture-related events in ancient Israel. Through the Amoraic period and into the Geonic period, this system was displaced by the mathematical rules used today; the principles and rules were codified by Maimonides in the Mishneh Torah in the 12th century.
Maimonides' work replaced counting "years since the destruction of the Temple" with the modern creation-era Anno Mundi. The Hebrew lunar year is about eleven days shorter than the solar year and uses the 19-year Metonic cycle to bring it into line with the solar year, with the addition of an intercalary month every two or three years, for a total of seven times per 19 years. With this intercalation, the average Hebrew calendar year is longer by about 6 minutes and 40 seconds than the current mean tropical year, so that every 217 years the Hebrew calendar will fall a day behind the current mean tropical year; the era used. As with Anno Domini, the words or abbreviation for Anno Mundi for the era should properly precede the date rather than follow it. AM 5779 began at sunset on 9 September 2018 and will end at sunset on 29 September 2019; the Jewish day is of no fixed length. The Jewish day is modeled on the reference to "...there was evening and there was morning..." in the creation account in the first chapter of Genesis.
Based on the classic rabbinic interpretation of this text, a day in the rabbinic Hebrew calendar runs from sunset to the next sunset. Halachically, a day ends and a new one starts when three stars are visible in the sky; the time between true sunset and the time when the three stars are visible is known as'bein hashmashot', there are differences of opinion as to which day it falls into for some uses. This may be relevant, for example, in determining the date of birth of a child born during that gap. There is no clock in the Jewish scheme. Though the civil clock, including the one in use in Israel, incorporates local adoptions of various conventions such as time zones, standard times and daylight saving, these have no place in the Jewish scheme; the civil clock is used only as a reference point – in expressions such as: "Shabbat starts at...". The steady progression of sunset around the world and seasonal changes results in gradual civil time changes from one day to the next based on observable astronomical phenomena and not on man-made laws and conventions.
In Judaism, an hour is defined as 1/12 of the time from sunrise to sunset, so, during the winter, an hour can be much less than 60 minutes, during the summer, it can be much more than 60 minutes. This proportional hour is known as a sha'ah z'manit. A Jewish hour is divided into parts. A part is 1/18 minute; the ultimate ancestor of the helek was a small Babylonian time period called a barleycorn, itself equal to 1/72 of a Babylonian time degree. These measures are not used for everyday purposes. Instead of the international date line convention, there are varying opinions as to where the day changes. One opinion uses the antimeridian of Jerusalem. Other opinions exist as well; the weekdays proceed to Saturday, Shabbat. Since some calculations use division, a remainder of 0 signifies Saturday. While calculations of days and years are based on fixed hours equal to 1/24 of a day, the beginning of each halachic day is based on the local time of sunset; the end of the Shabbat and other Jewish holidays is based on nightfall which occurs some amount of time 42 to 72 minutes, after sunset.
According to Maimonides, nightfall occurs. By the 17th century, this had become three-second-magnitude stars; the modern definition is when the center of the sun is 7° below the geometric horizon, somewhat than civil twilight at 6°. The beginning of the daytime portion of each day is determined both by sunrise. Most halachic times are based on some combination of these four times and vary from day to day throughout the year and vary depending on location; the daytime hours are divided into Sha'oth Zemaniyoth or "Halachic hours" by taking the time between sunrise and sunset or between dawn and nightfall and dividing it into 12 equal hours. The nighttime hours are s
The 12th century is the period from 1101 to 1200 in accordance with the Julian calendar in the Common Era. In the history of European culture, this period is considered part of the High Middle Ages and is sometimes called the Age of the Cistercians. In Song dynasty China an invasion by Jurchens caused a political schism of south; the Khmer Empire of Cambodia flourished during this century, while the Fatimids of Egypt were overtaken by the Ayyubid dynasty. China is under the Northern Song dynasty. Early in the century, Zhang Zeduan paints Along the River During the Qingming Festival, it will end up in the Palace Museum, Beijing. In southeast Asia, there is conflict between the Champa. Angkor Wat is built under the Hindu king Suryavarman II. By the end of the century the Buddhist Jayavarman VII becomes the ruler. Japan is in its Heian period; the Chōjū-jinbutsu-giga is made and attributed to Toba Sōjō. It ends up at the Kyoto. In Oceania, the Tuʻi Tonga Empire expands to a much greater area. Europe undergoes the Renaissance of the 12th century.
The blast furnace for the smelting of cast iron is imported from China, appearing around Lapphyttan, Sweden, as early as 1150. Alexander Neckam is the first European to document the mariner's compass, first documented by Shen Kuo during the previous century. Christian humanism becomes a self-conscious philosophical tendency in Europe. Christianity is introduced to Estonia and Karelia; the first medieval universities are founded. Pierre Abelard teaches. Middle English begins to develop, literacy begins to spread outside the Church throughout Europe. In addition, churchmen are willing to take on secular roles. By the end of the century, at least a third of England's bishops act as royal judges in secular matters; the Ars antiqua period in the history of the classical music of Western Europe begins. The earliest recorded miracle play is performed in England. Gothic architecture and trouvère music begin in France. During the middle of the century, the Cappella Palatina is built in Palermo and the Madrid Skylitzes manuscript illustrates the Synopsis of Histories by John Skylitzes.
Fire and plague insurance first become available in Iceland, the first documented outbreaks of influenza there happens. The medieval state of Serbia is formed by Stefan Nemanja and continued by the Nemanjić dynasty. By the end of the century, both the Capetian Dynasty and the House of Anjou are relying on mercenaries in their militaries. Paid soldiers are available year-round, unlike knights who expected certain periods off to maintain their manor lifestyles. In India, Hoysala architecture reaches a peak. In the Middle East, the icon of Theotokos of Vladimir is painted in Constantinople. Everything but the faces will be retouched, the icon will go to the Tretyakov Gallery of Moscow; the Georgian poet Shota Rustaveli composes his epic poem The Knight in the Panther's Skin. Shahab al-Din Suhrawardi founds his "school of illumination". In North Africa, the kasbah of Marrakesh is built, including the city gate Bab Agnaou and the Koutoubia mosque. In sub-Saharan Africa, Kente cloth is first woven. In France, the first piedfort coins in the history of numismatics were minted.
The city of Tula burns down, marking the end of the Toltec Empire List of 12th-century inventions 1104—The Venice Arsenal of Venice, Italy, is founded. It employed some 16,000 people for the mass production of sailing ships in large assembly lines, hundreds of years before the Industrial Revolution. 1106—Finished building of Gelati. 1107—The Chinese engineer Wu Deren combines the mechanical compass vehicle of the south-pointing chariot with the distance-measuring odometer device. 1111—The Chinese Donglin Academy is founded. 1165—The Liuhe Pagoda of Hangzhou, China, is built. 1170—The Christian notion of Purgatory is defined. 1185—First record of windmills. 1100: On August 5, Henry I is crowned King of England. 1100: On December 25, Baldwin of Boulogne is crowned as the first King of Jerusalem in the Church of the Nativity in Bethlehem. 1101: In July, the Treaty of Alton is signed between Henry I of England and his older brother Robert, Duke of Normandy in which Robert agrees to recognize Henry as king of England in exchange for a yearly stipend and other concessions.
The agreement temporarily ends a crisis in the succession of the Anglo-Norman kings. 1101–1103: David the Builder takes over Kakheti and Hereti. 1102: King Coloman unites Hungary and Croatia under the Hungarian Crown. 1102: Muslims conquer Señorio de Valencia 1103-1104: A church council is convened by King David the Builder in Urbnisi to reorganize the Georgian Orthodox Church. 1104: In the Battle of Ertsukhi, King David the Builder defeats an army of Seljuks. 1104: King Jayawarsa of Kadiri ascends to the throne. 1106: Battle of Tinchebray 1107–1111: Sigurd I of Norway becomes the first Norwegian king to embark on a crusade to the Holy Land. He fights in Lisbon and on various Mediterranean isles, helps the King of Jerusalem to take Sidon from the Muslims. 1108: By the Treaty of Devol, signed in September, Bohemond I of Antioch has to submit to the Byzantine Empire, becoming the vassal of Alexius I. 1109: On June 10, Bertrand of Toulouse captures the County of Tripoli. 1109: In the Battle of Nakło, Boleslaus III Wrymouth defeats the Pomeranians and re-establishes Polish access to the sea.
1109: On August 24, in the Battle of Hundsfeld, Boleslaus III Wrymouth defeats Emperor Henry V of Germany and stops German expansion eastward. 1111: On April 14, during Henry V's first expedition to Rome, he is crowned Holy Roman Emperor. 1113: Paramavishnulok is crowned as King Suryavarman II in Cambodia. He expands the Khmer Empire and builds Angkor Wat
The Rabbit is the fourth of the 12-year cycle of animals which appear in the Chinese zodiac related to the Chinese calendar. The Year of the Rabbit is associated with the Earthly Branch symbol 卯. In the Vietnamese zodiac and the Gurung zodiac, the cat takes the place of the Rabbit. People born within these date ranges can be said to have been born in the "Year of the Rabbit", while bearing the following elemental sign: Rabbit
Japanese calendar types have included a range of official and unofficial systems. At present, Japan uses the Gregorian calendar together with year designations stating the year of the reign of the current Emperor; the lunisolar Chinese calendar was introduced to Japan via Korea in the middle of the sixth century. After that, Japan calculated its calendar using various Chinese calendar procedures, from 1685, using Japanese variations of the Chinese procedures, but in 1873, as part of Japan's Meiji period modernization, a calendar based on the solar Gregorian calendar was introduced. In Japan today, the old Chinese calendar is ignored. Japan has had more than one system for designating years. Including: The Chinese sexagenary cycle was introduced early into Japan, it was used together with era names, as in the 1729 Ise calendar shown above, for "the 14th year of Kyōhō, tsuchi-no-to no tori", i.e. 己酉. Now, the cycle is used except around New Year; the era name system was introduced from China, has been in continuous use since AD 701.
Since the Taishō Emperor's ascension in 1912, each emperor's reign has begun a new era. Nengō are the official means of dating years in Japan, all government business is conducted using that system, it is in general use in private and personal business. The Japanese imperial year is based on the date of the legendary founding of Japan by Emperor Jimmu in 660 BC, it was first used in the official calendar in 1873. However, it never replaced era names, since World War II has been abandoned; the Western Common Era system has come into common use since the Meiji period. Now, most people know it, as well as era names; the official dating system known as nengō, has been in use since the late 7th century. Years are numbered within eras. Beginning with Meiji, each reign has been one era, but many earlier Emperors decreed a new era upon any major event; the nengō system remains in wide use on official documents and government forms. The imperial year system was used from 1872 to the Second World War. Imperial year 1 was the year when the legendary Emperor Jimmu founded Japan – 660 BC according to the Gregorian Calendar.
Usage of kōki dating can be a nationalist signal, pointing out that the history of Japan's imperial family is longer than that of Christianity, the basis of the Anno Domini system. Kōki 2600 was a special year; the 1940 Summer Olympics and Tokyo Expo were planned as anniversary events, but were canceled due to the Second Sino-Japanese War. The Japanese naval Zero Fighter was named after this year. After the Second World War, the United States occupied Japan, stopped the use of kōki by officials. Today, kōki is used, except in some judicial contexts; the 1898 law determining the placement of leap years is based on the kōki years, using a formula, equivalent to that of the Gregorian calendar: if the kōki year number is evenly divisible by four, it is a leap year, unless the number minus 660 is evenly divisible by 100 and not by 400. Thus, for example, the year Kōki 2560 is divisible by 4; the Japanese government has announced a new period of year on 2019 April Reiwa. The Heisei Period will end on 2019 April 30 and so the new period of year is expected to start on first of May 2019.
See "Seasonal days", below. The modern Japanese names for the months translate to "first month", "second month", so on; the corresponding number is combined with the suffix 月. The table below uses traditional numerals. In addition, every month has a traditional name, still used by some in fields such as poetry; the opening paragraph of a letter or the greeting in a speech might borrow one of these names to convey a sense of the season. Some, such as Yayoi and Satsuki, do double duty as given names; these month names appear from time to time on jidaigeki, contemporary television shows and movies set in the Edo period or earlier. The old Japanese calendar was an adjusted lunar calendar based on the Chinese calendar, the year—and with it the months—started anywhere from about 3 to 7 weeks than the modern year, so in historical contexts it is not accurate to equate the first month with January. Japan uses a seven-day week, aligned with the Western calendar; the seven-day week, with names for the days corresponding to the Latin system, was brought to Japan around AD 800 with the Buddhist calendar.
The system was used for astrological purposes and little else until 1876. The names of the days come from the five visible planets, which in turn are named after the five Chinese elements, from the moon and sun. On the origin of the names of the days of the week see East Asian Seven Luminaries. Sunday and Saturday are regarded as "Western style take-a-rest days". Since the late 19th century, Sunday has been regarded as a "full-time holiday", Saturday a half-time holiday; these holidays have no religious meaning. Many Japanese retailers
As a means of recording the passage of time, the 14th century was a century lasting from January 1, 1301, to December 31, 1400. During this period and natural disasters ravaged both Europe and the four khanates of the Mongol Empire; the Mongol court was driven out of China and retreated to Mongolia, the Ilkhanate collapsed in Persia, the Chaghatayid dissolved and broke into two parts, the Golden Horde lost its position as a great power in Eastern Europe. In Europe, the Black Death claimed between 75 and 200 million lives – wiping out over 60 percent of European society – while England and France fought in the protracted Hundred Years' War after the death of Charles IV, King of France led to a claim to the French throne by Edward III, King of England; this period is considered the height of chivalry and marks the beginning of strong separate identities for both England and France. The transition from the Medieval Warm Period to the Little Ice Age. Beginning of the Ottoman Empire, early expansion into the Balkans.
Early 14th century: Attributed to Kao Ninga Monk Sewing is made. Kamakura period, it is now kept at The Cleveland Museum of Art. An account of Buddha's life, translated earlier into Greek by Saint John of Damascus and circulated to Christians as the story of Barlaam and Josaphat, became so popular that the two were venerated as saints. Singapore emerges for the first time as a fortified trading centre of some importance. Islam reaches Terengganu, on the Malay Peninsula; the Hausa found several city-states in the south of modern Niger. The poet Petrarch coins the term Dark Ages to describe the preceding 900 years in Europe, beginning with the fall of the Western Roman Empire in 476 through to the renewal embodied in the Renaissance. Iwan vault, Jamé Mosque of Isfahan, Persia, is built. Work begins on the Great Enclosure at Great Zimbabwe, built of dressed stone; the city's population is now between 10,000 and 40,000. 1309 — King Jayanegara succeeds Kertarajasa Jayawardhana as ruler of Majapahit. 1309-1377 — The Avignon papacy transfers the seat of the Popes from Italy to France The Great Famine of 1315-1317 kills millions of people in Europe.
1318-1330 — An Italian Franciscan friar, Mattiussi visited Sumatra and Banjarmasin in Borneo. In his record he described the kingdom of Majapahit. 1320 — Władysław I the Elbow-high is crowned King of Poland which leads to its unification 1323 — Malietoafaiga ordered cannibalism to be abolished in Tutuila, now known as American Samoa. 1325 — Forced out of previous locations, the Mexica found the city of Tenochtitlan 1328 — Tribhuwana Wijayatunggadewi succeeds Jayanegara as ruler of Majapahit. Beginning of the Renaissance in Italy 1335 — The death of the Ilkhan Abu Said, causes the disintegration of the Mongol rule in Persia. 1336 — The Vijayanagara Empire is founded in South India by Harihara 1337 — The Hundred Years' War begins when Edward III of England lays claim to the French throne. 1345–1346 — The French recruit troops and ships in Genoa and Nice. 1346 — English forces led by Edward III defeat a French army led by Philip VI in The Battle of Crécy, a major point in the Hundred Years' War which marks the rise of the longbow as a dominant weapon in Western Europe.
1347–1351 — The Black Death kills around a third of the population of Europe. 1347 — Adityawarman moved the capital of Dharmasraya and established the kingdom of Malayupura in Pagarruyung, West Sumatra. 1350 — Hayam Wuruk, styled Sri Rajasanagara, succeeds Tribhuwana Wijayatunggadewi as ruler of Majapahit. Under its military commander Gajah Mada, Majapahit stretches over much of modern-day Indonesia. 1356 — The Imperial Diet of the Holy Roman Empire headed by Emperor Charles IV issues the Golden Bull of 1356, establishing various constitutional aspects of the Empire, the most significant being the electoral college to elect future emperors. 1356 — The Diet of the Hansa is held in Lübeck, formalising what up until had only been a loose alliance of trading cities in northern Europe and founding the Hanseatic League. 1357 — Scotland retains its independence with the signing of the Treaty of Berwick, thus ending the Wars of Scottish Independence. 1357 — In the Battle of Bubat, the Sundanese royal family is massacred by the Majapahit army by the order of Gajah Mada.
1363 — The Battle of Lake Poyang, a naval conflict between Chinese rebel groups led by Chen Youliang and Zhu Yuanzhang, takes place from August to October, constituting one of the largest naval battles in history. 1365 — The Old Javanese text Nagarakertagama is written. 1366 — Tepanec Tlatoani Acolnahuácatl accepts Acamapichtli as the first tlatoani of Tenochtitlan for the Mexica Empire. 1368 — The end of the Mongol Yuan Dynasty in China and the beginning of the Ming Dynasty. 1377 — Majapahit sends a punitive expedition against Palembang in Sumatra. Palembang's prince, Parameswara flees finding his way to Malacca and establishing it as a major international port. 1378 — The Great Schism of the West begins leading to 3 simultaneous popes. 1378-1382 — Ciompi Revolt occurs in Florence 1381 — John Wycliffe is dismissed from the University of Oxford for criticism of the Roman Catholic Church thus, the Lollardy movement rises in England. 1381 — Peasants' Revolt in England. 1385 — Battle of Aljubarrota between Portugal and Castile.
Portugal maintains independence. 1385 — Union of Krewo between Poland and Lithuania. 1389 — Battle of Kosovo between Serbs and Ottoman Turks, Prince Lazar, sultan Murat I and Miloš Obilić were killed. 1389 — Wikramawardhana succeeds Sri Rajasanagara as ruler of Majapahit. 1392 — Taejo
The Javanese calendar is the calendar of the Javanese people. It is used concurrently with the Gregorian calendar and the Islamic calendar; the Gregorian calendar is the official calendar of the Republic of Indonesia and civil society, while the Islamic calendar is used by Muslims and the Indonesian government for religious worship and deciding relevant Islamic holidays. The Javanese calendar is used by the main ethnicities of Java island—that is, the Javanese and Sundanese people—primarily as a cultural icon and identifier, as a maintained tradition of antiquity; the Javanese calendar is used for cultural and spiritual purposes. The current system of the Javanese calendar was inaugurated by Sultan Agung of Mataram in the Gregorian year 1633 CE. Prior to this, the Javanese had used the Hindu calendar, which begins in 78 CE and uses the solar cycle for calculating time. Sultan Agung's calendar retained the Saka calendar year system of counting, but differs by using the same lunar year measurement system as the Islamic calendar, rather than the solar year.
The Javanese calendar is referred to by its Latin name Anno Javanico or AJ. The Javanese calendar contains multiple, overlapping measurements of times, called "cycles"; these include: the native five-day week, called Pasaran the common Gregorian and Islamic seven-day week the Solar month, called Mangsa the Lunar month, called Wulan the lunar year, or Tahun the octo-ennia cycles, or Windu the 120-year cycle of 15 Windu, called Kurup Days in the Javanese calendar, like the Islamic calendar, begin at sunset. Traditionally, Javanese people do not divide the night into hours, but rather into phases; the division of a day and night are: The native Javanese system groups days into a five-day week called Pasaran, unlike most calendars that uses a seven-day week. The name, pasaran, is derived from the root word pasar, but still today, Javanese villagers gather communally at local markets to meet, engage in commerce, buy and sell farm produce, cooked foods, home industry crafted items and so on. John Crawfurd suggested that the length of the weekly cycle is related to the number of fingers on the hand, that itinerant merchants would rotate their visits to different villages according to a five-day "roster".
The days of the cycle each have two names, as the Javanese language has distinct vocabulary associated with two different registers of politeness: ngoko and krama. The krama names for the days, second in the list, are much less common. ꦊꦒꦶ – ꦩꦤꦶꦱ꧀ ꦥꦲꦶꦁ – ꦥꦲꦶꦠ꧀ ꦥꦺꦴꦤ꧀ – ꦥꦼꦠꦏ꧀ ꦮꦒꦺ – ꦕꦼꦩꦺꦁ ꦏ꧀ꦭꦶꦮꦺꦴꦤ꧀ – ꦲꦱꦶꦃ The origin of the names is unclear, their etymology remains obscure. The names may be derived from indigenous gods, like the European and Asian names for days of the week. An ancient Javanese manuscript illustrates the week with five human figures: a man seizing a suppliant by the hair, a woman holding a horn to receive an offering, a man pointing a drawn sword at another, a woman holding agricultural produce, a man holding a spear leading a bull. Additionally, Javanese consider these days' names to have a mystical relation to colors and cardinal direction: Legi: white and East Pahing: red and South Pon: yellow and West Wage: black and North Kliwon: blurred colors/focus and'center'. Most Markets no longer operate under this traditional Pasaran cycle, instead pragmatically remaining open every day of the Gregorian week.
However many markets in Java still retain traditional names that indicated that once the markets only operated on certain Pasaran days, such as Pasar Legi, or Pasar Kliwon. Some markets in small or medium size locations will be much busier on the Pasaran day than on the other days. On the market's name day itinerate sellers appear selling such things as livestock and other products that are either less purchased or are more expensive; this allows a smaller number of these merchants to service a much larger area much as in bygone days. Javanese astrological belief dictates that an individual’s characteristics and destiny are attributable to the combination of the Pasaran day and the "common" weekday of the Islamic calendar on that person's birthday. Javanese people find great interest in the astrological interpretations of this combination, called the Wetonan cycle; the seven-day-long week cycle is derived from the Islamic calendar, adopted following the spread of Islam throughout the Indonesian archipelago.
The names of the days of the week in Javanese are derived from their Arabic counterparts, namely: These two-week systems occur concurrently. This combination forms the Wetonan cycle; the Wetonan cycle superimposes the five-day Pasaran cycle with the seven-day week cycle. Each Wetonan cycle lasts for 35 days. An example of Wetonan cycle: From the example above, the Weton for Tuesday May 6, 2008 would be read as Selasa Wage; the Wetonan cycle is important for divinatory systems, important celebrations, rites of passage. Commemorations and events are held on days considered to be auspicious. An prominent example, still taught in primary schools, is that the Weton for the Proclamation of Indonesian Independence on 17 August 1945 took place on Jumat Legi. Therefore, Jumat Legi is considered an important night for pilgrimage. There are taboos
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