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
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 8th century is the period from 701 to 800 in accordance with the Julian calendar in the Common Era. The coast of North Africa and the Iberian Peninsula come under Islamic Arab domination; the westward expansion of the Umayyad Empire was famously halted at the Siege of Constantinople by the Byzantine Empire and the Battle of Tours by the Franks. The tide of Arab conquest came to an end in the middle of the 8th century. In Europe, late in the century, the Vikings, seafaring peoples from Scandinavia, begin raiding the coasts of Europe and the Mediterranean, go on to found several important kingdoms. In Asia, the Pala Empire is founded in Bengal; the Tang dynasty reaches its pinnacle under Chinese Emperor Xuanzong. The Nara period begins in Japan. Estimated century in which the poem Beowulf is composed. Classical Maya civilization begins to decline; the first Serbian state is formed at the beginning of the century. Borobodur, the famous Indonesian Buddhist structure, begins construction as a non-Buddhist shrine.
Buddhist Jataka stories are translated into Arabic as Kalilag and Damnag. An account of Buddha's life is translated into Greek by Saint John of Damascus, circulated to Christians as the story of Barlaam and Josaphat. Height of the Classic period in pre-Columbian Maya civilization history. Śāntideva, a Buddhist monk at Nalanda Monastery in India, composes the famous Bodhicharyāvatāra, or Guide to the Bodhisattva's Way of Life. The height of the Giant Wild Goose Pagoda in Xian, China is extended by 5 stories. 701: The Taihō Code is enacted in late Asuka period Japan. 705: Overthrow of Empress Wu Zetian, the reign of China's first and only sole-ruling empress ends. 705: Justinian II is forced to give the title Caesar of Byzantium to the Bulgarian Emperor Tervel. The Byzantine Empire begins to pay annual tributes to Bulgaria. 708 – 711: The Bulgarians defeat Justinian II at the battle of Anchiallus. Arab armies occupied Sindh. 710: Empress Genmei moves the capital to Heijō-kyū, initiating the Nara period of Japan.
711: Palenque is conquered by Toniná. 711: Tariq ibn Ziyad crosses the Straits of Gibraltar. With the creation of Al-Andalus, most of the Iberian Peninsula is conquered by Arab and Berber Muslims, thus ending the Visigothic rule, beginning eight centuries of Muslim rule. 712: Liutprand, King of the Lombards begins his reign. C. 712: Metropolitan episcopal see is established by the Church of the East in Chinese capital of Chang'an. 712 – 756: Emperor Xuanzong reigned, the time was considered one of China's high points. 712 – 740: Caliphate campaigns in India 713: Death of Dajian Huineng and last Patriarch of Chán Buddhism. 717 – 718: Siege of Constantinople. The Bulgarians and the Byzantines decisively defeat the invading Arabs, thus halting the Arab advance toward Europe. 718: Sri Indravarman King of Srivijaya send a letter to the Caliph Umar bin Abdul Aziz of the Umayyad Caliphate in Damascus, signing early ancient Indonesian official contact with Islamic world in the Middle East. 726: Byzantine Emperor Leo III the Isaurian destroys the icon of Christ above the Chalke Gate in the capital city of Constantinople, beginning the first phase of the Byzantine Iconoclasm.
731: Bede completes his Historia ecclesiastica gentis Anglorum. 732: Battle of Tours. Near Poitiers, leader of the Franks Charles Martel and his men defeat a large army of Moors under the governor of Cordoba, Abdul Rahman Al Ghafiqi, killed during the battle; the Battle of Tours halts the advance of Islam into Western Europe and establishes a balance of power between Western Europe and the Byzantine Empire. 732: The Sanjaya dynasty is founded around this time according to the Canggal inscription. 738: Quiriguá declares independence from Copan 740: Battle of Akroinon. Byzantines win their first large-scale victory in a pitched battle against the Arabs. 742: For the municipal census of the Tang-dynasty Chinese capital city Chang'an and its metropolitan area of Jingzhou Fu, the New Book of Tang records that in this year there were 362,921 registered families with 1,960,188 persons. 748: The Chinese Buddhist monk Jian Zhen writes in his Yue Jue Shu of the international sea traffic coming to Guangzhou, ships from Borneo, Sri Lanka and others bringing tons of goods.
750: The last Umayyad Caliph Marwan II is overthrown and executed by the first Abbasid Caliph, Abu al-Abbas al-Saffah. The Caliphate is moved to Baghdad which would develop into a centre of trade and culture; the Ghana Empire begins in western Africa. Mid-8th century - Great Wild Goose Pagoda at Ci'en Temple, Xi'an, Shanxi, is rebuilt. C. mid-8th century - Camel Carrying a Group of Musicians, from a tomb near Xi'an, Shanxi, is made. Tang dynasty, it is now kept at Museum of Beijing. 751: Arabian armies defeat Chinese Tang dynasty troops in the Battle of Talas, in the high Pamirs near Samarkand, conquer Central Asia completely. 752: The Hindu Medang kingdom flourishes and declines. 755 – 763: The An Shi Rebellion devastates China during the mid Tang dynasty. 757: King Offa of Mercia becomes dominant ruler in England. 758: Arab and Persian pirates and travelers burn and loot the Chinese city of Guangzhou, while the Tang Dynasty authorities shut the port down for the next five decades. 760: The construction of Borobudur started.
768: Pepin dies. 770's – 780's: Java launched series of naval raids on ports of Dai Viet and Cambodia. The naval raids was launched by Sailendran-Srivijayan Maharaja
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
Enryaku was a Japanese era name after Ten'ō and before Daidō. This period spanned the years from August 782 through May 806; the reigning emperor was Kanmu-tennō. November 12, 782 Enryaku gannen: The new era name was created to mark an series of events; the previous era ended and the new one commenced in Ten'ō 2, on the 19th day of the 8th month of 782. 782: The sadaijin Fujiwara no Uona was removed from his office and exiled to Kyushu. Some time the emperor did permit him to return to the capital where he died. In the same general time frame, Fujiwara no Tamaro was named udaijin. During these days in which the offices of sadaijin and udaijin were vacant, the major counselors and the emperor assumed responsibilities and powers which would have been otherwise delegated. 783: The udaijin Tamaro died at the age of 62 years. 783: Fujiwara no Korekimi became the new udaijin to replace the late Fujiwara no Tamaro. 793: Under the leadership of the Buddhist priest Dengyō, construction is begun on the Enryaku Temple.
December 17, 794: The Emperor moves by carriage in a grand procession from Nara to Heian-kyō. 796: Additional copper coins were put into circulation, each bearing the legend Ren-hei Ei-hō. 806: Emperor Kanmu's reign lasted for 25 years. He died at the age of 70, he was buried in the neighborhood of Momoyama. In 1894, another tomb was created, his spirit is said to rest in peace next to the tomb of Emperor Meiji at this shrine. Appert and Hiroshi Kinoshita.. Ancien japon. Tokyo: Kokubunsha. OCLC 458497085 Brown, Delmer M. and Ichirō Ishida, eds.. Gukanshō: The Future and the Past. Berkeley: University of California Press. ISBN 978-0-520-03460-0. Japan encyclopedia. Cambridge: Harvard University Press. ISBN 978-0-674-01753-5. Nihon Ōdai Ichiran. Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. OCLC 5850691 Varley, H. Paul.. A Chronicle of Gods and Sovereigns: Jinnō Shōtōki of Kitabatake Chikafusa. New York: Columbia University Press. ISBN 9780231049405.
The 7th century is the period from 601 to 700 in accordance with the Julian calendar in the Common Era. The Muslim conquests began with the unification of Arabia by Muhammad starting in 622. After Muhammad's death in 632, Islam expanded beyond the Arabian Peninsula under the Rashidun Caliphate and the Umayyad Caliphate; the Islamic conquest of Persia in the 7th century led to the downfall of the Sassanid Empire. Conquered during the 7th century were Syria, Armenia and North Africa; the Byzantine Empire continued suffering setbacks during the rapid expansion of the Muslim Empire. In the Iberian Peninsula, the 7th century was the Siglo de Concilios, that is, century of councils, referring to the Councils of Toledo. In China, the Sui dynasty was replaced by the Tang dynasty, which set up its military bases from Korea to Central Asia, was next to the Umayyad's later. China began to reach its height. Silla allied itself with the Tang Dynasty, subjugating Baekje and defeating Goguryeo to unite the Korean Peninsula under one ruler.
The Asuka period persisted in Japan throughout the 7th century. Harsha united Northern India, which had reverted to small republics and states after the fall of the Gupta Empire in the 6th century. Islam begins in Arabia; the first known Croatian archon Porga establishes the Duchy of Croatia. The world's population shrinks to about 208 million people; the Anglo-Saxon Heptarchy emerges at the last in England. Sutton Hoo ship burial, East Anglia. Xuanzang traveled from China to India, before returning to Chang'an in China to translate Buddhist scriptures. Timgad, Algeria, is destroyed by Berbers. End of sporadic Buddhist rule in the Sindh. Croats enter their present territory early in the 7th century, settling in six distinct tribal delimitations. Teotihuacan is sacked; the political and religious buildings are burned. The religion of Shugendo evolves from Buddhism, Taoism and other influences in the mountains of Japan; the Bulgars arrive in the Balkans. Arab traders penetrate the area of Lake Chad. Earliest attested English poetry.
Side panels, Basilica of Sant'Apollinare in Classe, are made. Main compound, Horyu-ji, Nara Prefecture, is built. Asuka period. 7th and 9th century – Mosaics above apse, Basilica of Sant'Apollinare in Classe, are made. 600: Smallpox spreads from India into Europe. 602: The Third Chinese domination of Vietnam starts following the collapse of the Early Lý dynasty. 603: Last mention of the Roman Senate in Gregorian Register. It mentions that the senate empress Leontia. 606: Boniface elected papal successor on the death of Pope Sabinian. He sought and obtained a decree from Byzantine Emperor Phocas which stated that "the See of Blessed Peter the Apostle should be the head of all the Churches"; this ensured that the title of "Universal Bishop" belonged to the Bishop of Rome. 607: Hōryū-ji temple believed to have been completed by 607 in Ikaruga, Japan. 610: Heraclius arrives by ship from Africa at Constantinople, overthrows East Roman Emperor Phocas and becomes Emperor. His first major act is to change the official language of the East Roman Empire from Latin to Greek.
615: The Sassanid Empire under Shah Khosrau II sacks Jerusalem, taking away the relic of the True cross. 615: Pacal the Great becomes king of the Mayan city-state of Palenque 616: Shah Chosroes II invades Egypt. 616: Aethelfrith of Northumbria defeats the Welsh in a battle at Chester in England. 618: Tang Dynasty of China do initiated by Li Yuan. 618: The Chenla kingdom absorbed Funan. Guangzhou, becomes a major international seaport, hosting maritime travelers from Egypt, East Africa, Persia, Sri Lanka, South East Asia, including Muslims, Jews and Nestorian Christians. 622: Year one of the Islamic calendar begins, during which the Hijra occurs—Muhammad and his followers emigrate from Mecca to Medina in September. 623: The Frankish merchant Samo, supporting the Slavs fighting their Avar rulers, becomes the ruler of the first known Slav state in Central Europe. 626: The Avars and the Persians jointly besiege but fail to capture Constantinople. 627: Emperor Heraclius defeats the Persians, ending the Roman-Persian Wars.
629: The Byzantine-Arab Wars begin. Much of the Roman Empire is conquered by Muslim Arabs led by Khalid ibn al-Walid. 629–630: Emperor Taizong's campaign against Eastern Tujue, Chinese Tang Dynasty forces under commanders Li Jing and Li Shiji destroy the Göktürk Khanate. 632: The Muslim conquests begin. 635-649: Alopen, a Persian Christian priest introduces Nestorian Christianity into China. 636: Around this time the Battle of al-Qādisiyyah resulted in a decisive victory for Muslims in the Islamic conquest of Persia, the Persian Empire is conquered by Muslim Arabs led by Sad Ibn Abi Waqqas. 638: Emperor Taizong issues an edict of universal toleration of religions. 639: Muslim conquest of Egypt and Armenia. 639: Unsuccessful revolt of Ashina Jiesheshuai of the Turkic people against Tang China. 641: The Coptic period, in its more specific definition, ends when Islam is introduced into Egypt. 649-683: Chinese Emperor Gaozong permits establishment of Christian monasteries in each of 358 prefectures.
650: The Khazar-Arab Wars begin. Mid-7th century – Durga Mahishasura-mardini, rock-cut relief, Tamil Nadu, India, is made. Pallava period, it is now kept at University of Michigan, Ann Arbor. Mid-7th century - Portrait of Lord Pacal, from his tomb, Temple of the Inscripti
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