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 1st century was the century AD 1 to AD 100 according to the Julian calendar. It is written as the 1st century AD or 1st century CE to distinguish it from the 1st century BC which preceded it; the 1st century is considered part of epoch, or historical period. During this period, North Africa and the Near East fell under increasing domination by the Roman Empire, which continued expanding, most notably conquering Britain under the emperor Claudius; the reforms introduced by Augustus during his long reign stabilized the empire after the turmoil of the previous century's civil wars. In the century the Julio-Claudian dynasty, founded by Augustus, came to an end with the suicide of Nero in AD 68. There followed the famous Year of Four Emperors, a brief period of civil war and instability, brought to an end by Vespasian, ninth Roman emperor, founder of the Flavian dynasty; the Roman Empire experienced a period of prosperity and dominance in this period and the First Century is remembered as part of the Empire's golden age.
The 1st century saw the appearance of Christianity. China continued to be dominated by the Han Dynasty, despite a fourteen-year interruption by the Xin dynasty under Wang Mang. Han rule was restored in AD 23; the capital was moved from Chang'an to Luoyang. Western Europe: Celtic, Germanic and Finnic tribal chiefdom and the Roman Empire Eastern Europe: Roman Empire, Sarmatian and Balt tribal chiefdoms North Africa: Roman Empire, Mauri and Gaetulian tribal chiefdoms West Africa: Gur, Kwa and Mande tribal chiefdoms Central Africa: Bantu tribes, collapsing Nok culture Nok civilization East Africa: Kingdom of Kush, Kingdom of Blemmyes, Kingdom of Aksum Southern Africa: Bantu tribes, Khoisan. Western Asia: Roman and Parthian Empires and Arabian Kingdoms, smaller tribes. Central Asia: Kushan Empire, Sarmatian and other Iranian tribal chiefdoms South Asia: Kushan Empire, Western Satraps, Satavahana Empire, Dravidian Kingdoms, Kingdom of Kalinga, Indo-Parthian Kingdom, Zhangzhung. Southeast Asia: Mandala of city-states, Kingdom of Funan East Asia: Han Dynasty, Yamatai and Xianbei tribal chiefdoms, Three Kingdoms of Korea.
North America: Central America: Mayan and Zapotec civilizations. Caribbean: South America: Nazca, Moche civilizations, Tairona tribal chiefdoms. Early 1st century – Augustus of Primaporta, is made, it is now kept in Braccio Nuovo, Rome. Early 1st century – Gemma Augustea is made, it is now kept at Vienna. Early 1st century – House of the Silver Wedding, Pompeii, is built. Excavated in 1893, the year of the silver wedding anniversary of Italy's King Humbert and his wife, Margherita of Savoy, who have supported archaeological fieldwork at Pompeii. Early 1st century - Inner shrine, Mie, Mie Prefecture, is built. Yayoi period. AD 1: Lions became extinct in Western Europe. AD 2: First census of China, the census is one of the most accurate in Chinese history. AD 6: Census of Quirinius. AD 7: Prince Cunobeline of Catuvellauni defeats the Trinovantes in England and establishes his capital at Camulodunum. AD 9: Three Roman legions were ambushed and destroyed at Teutoberg Forest by Germans under the leadership of Arminius.
AD 9: Prince Cunobeline is crowned King of Catuvellauni, his Kingdom dominates Southern England. AD 9 – 23: Wang Mang temporarily overthrew the Han dynasty of China. AD 9 – 23: Xin dynasty. AD 14: Augustus Caesar, first emperor of Rome, dies, his adopted son and son-in-law Tiberius is his successor. AD 25: The Han dynasty is restored by Liu Xiu who proclaims himself Emperor Guangwu of Han. AD 28 – 75: Emperor Ming of Han, Buddhism reaches China. Humans establish the Bunlap tribe, among others. C. AD 29: Jesus begins his ministry. C. AD 33: The Crucifixion of Jesus. C. AD 33 – 36: Conversion of Paul the Apostle. AD 40: Succession crisis erupts at King Cunobeline's court and his exiled younger son Prince Adminius flees to the court of Caligula in Rome. AD 40: Emperor Caligula plans to invade Britain, but forgets to bring an army, he instead declares war upon the sea, whipping it and taking shells as prisoners. AD 40 – 43: Revolts erupts in Vietnam by the Trung sisters. AD 42: King Cunobeline dies, his son Caratacus becomes King.
He and his brother conquer much of South-Eastern England, expanding territory into Atrebates, driving out King Verica. King Verica travels to Rome to the court of Claudius to help reclaim his throne. AD 43: Roman conquest of Britain begins. London is founded. AD 44: Death of Herod Agrippa. AD 41 – 54: Rachias, an ambassador sent from Sri Lanka to the court of Claudius. Buddhist monks in Sri Lanka first write down Buddha's teachings, creating the Pali canon; the regions of present-day Afghanistan and North India come under the control of the Kushans, a nomadic people forced out of northwest China by the Han Dynasty. Tacitus mentions the Suiones. Kaundinya, an Indian brahmin establishes the pre-Angkor Cambodian Kingdom of Funan; the Goths settle in northern Poland, which they called Gothiscandza, shape the Wielbark culture. C. AD 50: Christian Council of Jerusalem. Mid-1st century – Wall niche, from garden in Pompeii, is made, it is now kept at University of Cambridge, England. Mid-1st century – Detail of a wall painting in the House of M. Lucretius Fronto, Pompeii
The Byzantine calendar called "Creation Era of Constantinople" or "Era of the World", was the calendar used by the Eastern Orthodox Church from c. 691 to 1728 in the Ecumenical Patriarchate. It was the official calendar of the Byzantine Empire from 988 to 1453, of Kievan Rus' and Russia from c. 988 to 1700. Since "Byzantine" is a historiographical term, the original name uses the noun "Roman" as it was how the Eastern Roman Empire continued calling itself; the calendar was based on the Julian calendar, except that the year started on 1 September and the year number used an Anno Mundi epoch derived from the Septuagint version of the Bible. It placed the date of creation at 5509 years before the Incarnation, was characterized by a certain tendency, a tradition among Jews and early Christians to number the years from the calculated foundation of the world, its Year One, marking the supposed date of creation, was September 1, 5509 BC, to August 31, 5508 BC. It is not known when; the first appearance of the term is in the treatise of a certain "monk and priest", who mentions all the main variants of the "World Era" in his work.
Georgios argues that the main advantage of the World era is the common starting point of the astronomical lunar and solar cycles, of the cycle of indictions, the usual dating system in Byzantium since the 6th century. He already regards it as the most convenient for the Easter computus. Complex calculations of the 19-year lunar and 28-year solar cycles within this world era allowed scholars to discover the cosmic significance of certain historical dates, such as the birth or the crucifixion of Jesus; this date underwent minor revisions before being finalized in the mid-7th century, although its precursors were developed c. AD 412. By the second half of the 7th century, the Creation Era was known in Western Europe, at least in Great Britain. By the late 10th century around AD 988, when the era appears in use on official government records, a unified system was recognized across the Eastern Roman world; the era was calculated as starting on September 1, Jesus was thought to have been born in the year 5509 since the creation of the world.
Historical time was thus calculated from the creation, not from Christ's birth, as in the west after the Anno Domini system was adopted between 6th and 9th centuries. The Eastern Church avoided the use of the Anno Domini system of Dionysius Exiguus, since the date of Christ's birth was debated in Constantinople as late as the 14th century. Otherwise the Byzantine calendar was identical to the Julian Calendar except that: the names of the months were transcribed from Latin into Greek; the leap day of the Byzantine calendar was obtained in an identical manner to the bissextile day of the original Roman version of the Julian calendar, by doubling the sixth day before the calends of March, i.e. by doubling 24 February. The Byzantine World Era was replaced in the Orthodox Church by the Christian Era, utilized by Patriarch Theophanes I Karykes in 1597, afterwards by Patriarch Cyril Lucaris in 1626, formally established by the Church in 1728. Meanwhile, as Russia received Orthodox Christianity from Byzantium, she inherited the Orthodox Calendar based on the Byzantine Era.
After the collapse of the Byzantine Empire in 1453, the era continued to be used by Russia, which witnessed millennialist movements in Moscow in AD 1492. It was only in AD 1700 that the Byzantine World Era in Russia was changed to the Julian Calendar by Peter the Great, it still forms the basis of traditional Orthodox calendars up to today. September AD 2000 began the year 7509 AM; the earliest extant Christian writings on the age of the world according to the Biblical chronology are by Theophilus, the sixth bishop of Antioch from the Apostles, in his apologetic work To Autolycus, by Julius Africanus in his Five Books of Chronology. Both of these early Christian writers, following the Septuagint version of the Old Testament, determined the age of the world to have been about 5,530 years at the birth of Christ. Ben Zion Wacholder points out that the writings of the Church Fathers on this subject are of vital significance, in that through the Christian chronographers a window to the earlier Hellenistic biblical chronographers is preserved: An immense intellectual effort was expended during the Hellenistic period by both Jews and pagans to date creation, the flood, building of the Temple...
In the course of their studies, men such as Tatian of Antioch, Clement of Alexandria, Hippolytus of Rome
The 2nd century is the period from 101 to 200 in accordance with the Julian calendar in the Common Era. It is considered part of epoch, or historical period. Early in the century, the Roman Empire attained its greatest expansion under the emperor Trajan, but after his death became defensive for the rest of its history. Much prosperity took place throughout the empire at this time, ruled as it were by the Five Good Emperors, a succession of well-received and able rulers; this period saw the removal of the Jews from Jerusalem during the reign of Hadrian after Bar Kokhba's revolt. The last quarter of the century saw the end of the period of peace and prosperity known as the Pax Romana at the death of the emperor Marcus Aurelius, last of the "Five Good Emperors", the ascension of Commodus. After Commodus was murdered in 192, a turbulent period known as the Year of the Five Emperors ensued, after the quick successive removals of Pertinax and Didius Julianus from power, had the general-turned-emperor Septimius Severus, founder of the Severan dynasty, pitted against rival claimants in the form of Pescennius Niger, whom his forces defeated at the Battle of Issus in 194, Clodius Albinus, whom he defeated at the Battle of Lugdunum in 197, granting him sole authority over the empire.
Although the Han Dynasty of China was cemented into power and extended its imperial influence into Central Asia during the first half of the century, by the second half there was widespread corruption and open rebellion. This set in motion its ultimate decline, in September 189, the Han general Dong Zhuo, after being summoned to the capital by He Jin to help quell the corrupt and powerful eunuch faction by serving as an intimidator to both them and the Empress Dowager, marched his army into Luoyang in light of He Jin's assassination and the subsequent slaughter of the eunuchs, taking over the capital and becoming the de facto head of the government, although warlords and government officials took against him in a campaign that, while failing to put him down, compelled Dong Zhuo to shift the seat of imperial power further west to Chang'an; as Dong Zhuo was killed in 192, the chaos in the wake of the collapse of centralized authority only continued, with various warlords attempting to vye for supremacy in order to establish or hold onto their authority within the decaying empire.
Meanwhile, Dong Zhuo's former followers Li Jue and Guo Si were left to squabble amongst themselves, while the emperor himself fled and returned to the ravaged city of Luoyang, but shortly thereafter, in 196, was given refuge by the warlord Cao Cao, who relocated him to the new capital city of Xu, from where Cao Cao could control the emperor. Cao Cao would only further exert his authority by defeating the powerful warlord Yuan Shao at the decisive Battle of Guandu in 200. AD 96 – 180: Five Good Emperors of Rome: Nerva, Hadrian, Antoninus Pius, Marcus Aurelius. 100 - 200: The Grand Anicut an ancient dam is constructed by a Chola king. The Kingdom of Aksum emerges. 101 – 102, 105 – 106: The Dacian Wars. After two conflicts, Dacia is annexed as a Roman province. 114 – 116: A war with Parthia results in Armenia and Mesopotamia being temporarily annexed into the Roman Empire. 115 – 117: Kitos War, adjunct to the Jewish–Roman wars. 122 – 132: Hadrian's Wall across Northern England. 127 – 140: Kanishka, Kushan Ruler.
132 – 135: Bar Kokhba's revolt against Rome. 132: Chinese chronicles described the existence of diplomatic relations between Java and China. 140 – 180: Huvishka, Kushan ruler. 142 – 154: The Antonine Wall is built across central Scotland. 144: Marcion, rejected by Church of Rome, founds Marcionism. 161 – 166: Roman–Parthian War of 161–166. 165 – 180: The Antonine Plague in Rome. 166 – 180: Marcomannic Wars. 166 – 184: Disasters of the Partisan Prohibitions. 180 – 192: Commodus, Roman Emperor. 184 – 205: The Yellow Turban Rebellion of the Han Dynasty in China begins. 184 – 189: The Liang Province Rebellion breakouts in Northwest China. 189 – 220: The End of the Han dynasty. 190 – 191: Warlords across China launches a Campaign against Dong Zhuo. 193: Roman Year of the Five Emperors. 193 – 211: Septimius Severus, Roman Emperor. Herakleitos makes The Unswept Floor, mosaic variant of a 2nd-century BC painting by Sosos of Pergamon, it is now kept in Rome. C. 2nd or 3rd century – Standing Buddha, from Gandhara, is made.
Kushan period. It is now kept at Lahore. Antoninus Pius, Roman Emperor Cai Yong, Chinese scholar Commodus, Roman Emperor Dong Zhuo, Chinese general and warlord Hadrian, Roman Emperor Huvishka, Kushan Ruler Ignatius, third bishop of Antioch, author of letters Irenaeus, second bishop of Lyon, author of Against the Heresies Julia Domna, Empress of Rome Justin Martyr, Christian apologist Kanishka, Kushan ruler Karikala, King of the Chola dynasty who constructed the Grand Anicut dam for farmers in Tamilnadu Kong Rong, Chinese scholar Lü Bu, Chinese general and warlord Lucius Verus, Roman Emperor Marcus Aurelius, Roman Emperor, philosopher Montanus, Christian heretic. Nagarjuna, founder of Madhyamaka Buddhism Polycarp, bishop of Smyrna. Rabbi Akiva, Head of the Jewish Sages Rabbi Yehuda haNasi, redactor of the Mishnah Septimius Severus, Roman Emperor Simon bar Kokhba, Jewish rebel leader Sun Ce, Chinese general and warlord Trajan, Roman Emperor Victor I, bishop of Rome. Vologases IV, Parthian ruler Vologases V, Parthian ruler Wang Yun, Chinese official Qiao Xuan, Chinese official Yuan Shao, Chinese warlord Yuan Shu, Chinese warlord Zhang Daoling, Chinese Taoist hermit.
Zhang Heng, Chinese statesman, inventor, astronomer and engineer. Zhang Jue, Chinese rebel leader Zhang Zhongjing, one of the most famous Chinese physicians during Han Dynasty. Achilles Tatius
The Nanakshahi calendar is a tropical solar calendar, used in Sikhism and is based on the'Barah Maha'. Barah Maha was composed by the Sikh Gurus and translates as the "Twelve Months", it is a poem reflecting the changes in nature which are conveyed in the twelve-month cycle of the Year. The year begins with 1 Chet corresponding to 14 March; the first year of the Nanakshahi Calendar starts in 1469 CE: the year of the birth of Guru Nanak Dev. The Nanakshahi Calendar is named after the founder of Guru Nanak Dev. Sikhs have traditionally recognised luni-solar calendars: the Nanakshahi and Khalsa. Traditionally, both these calendars followed the Bikrami calendar with the Nanakshahi year beginning on Katak Pooranmashi and the Khalsa year commencing with Vaisakhi; the methods for calculating the beginning of the Khalsa era were based on the Bikrami calendar. The year length was the same as the Bikrami solar year. According to Steel, the calendar has twelve lunar months that are determined by the lunar phase, but thirteen months in leap years which occur every 2–3 years in the Bikrami calendar to sync the lunar calendar with its solar counterpart.
Kay abbreviates the Khalsa Era as KE. References to the Nanakshahi Era have been made in historic documents. Banda Singh Bahadur adopted the Nanakshahi calendar in 1710 C. E. after his victory in Sirhind according to which the year 1710 C. E. became Nanakshahi 241. However, Singh states the date of the victory as 14 May 1710 CE. According to Dilagira, Banda "continued adopting the months and the days of the months according to the Bikrami calendar". Banda Singh Bahadur minted new coins called Nanakshahi. Herrli states. Although Banda may have proclaimed this era, it cannot be traced in contemporary documents and does not seem to have been used for dating". According to The Panjab Past and Present, it is Gian Singh who "is the first to use Nanak Shahi Samvats along with those of Bikrami Samvats" in the Twarikh Guru Khalsa. According to Singha, Gian Singh was a Punjabi author born in 1822. Gian Singh wrote the Twarikh Guru Khalsa in 1891; the revised Nanakshahi calendar was designed by Pal Singh Purewal to replace the Bikrami calendar.
The epoch of this calendar is the birth of the first Sikh Guru, Nanak Dev in 1469 and the Nanakshahi year commences on 1 Chet. New Year's Day falls annually on; the start of each month is fixed. According to Kapel, the solar accuracy of the Nanakshahi calendar is linked to the Gregorian civil calendar; this is because the Nanaskhahi calendar uses the tropical year instead of using the sidereal year, used in the Bikrami calendar or the old Nanakshahi and Khalsa calendars. The amended Nanakshahi calendar was adopted in 1998 but implemented in 2003 by the Shiromani Gurdwara Prabhandak Committee to determine the dates for important Sikh events; the calendar was implemented during the SGPC presidency of Sikh scholar Prof. Kirpal Singh Badungar at Takhat Sri Damdama Sahib in the presence of Sikh leadership. Nanakshahi Calendar recognizes the adoption event, of 1999 CE, in the Sikh history when SGPC released the first calendar with permanently fixed dates in the Tropical Calendar. Therefore, the calculations of this calendar do not regress back from 1999 CE into the Bikrami era, fixes for all time in the future.
Features of the Original Nanakshahi calendar: Uses the accurate Tropical year rather than the Sidereal year Called Nanakshahi after Guru Nanak Year 1 is the Year of Guru Nanak's Birth. As an example, April 14, 2019 CE is Nanakshahi 551. Is Based on Gurbani – Month Names are taken from Guru Granth Sahib Contains 5 Months of 31 days followed by 7 Months of 30 days Leap year every 4 Years in which the last month has an extra day Approved by Akal Takht in 2003 In 2010, the Shiromani Gurdwara Prabhandak Committee modified the calendar so that the dates for the start of the months are movable so that they coincide with the Bikrami calendar and changed the dates for various Sikh festivals so they are based upon the lunar phase; this has created controversy with some bodies adopting the original 2003 version called the "Mool Nanakshahi Calendar" and others, the 2010 version. By 2014, the SGPC had scrapped the original Nanakshahi calendar from 2003 and reverted to the Bikrami calendar however it was still published under the name of Nanakshahi.
The Sikh bodies termed it a step taken under pressure from the Shiromani Akali Dal. There is some controversy about the acceptance of the calendar altogether among certain sectors of the Sikh world. SGPC president, Gobind Singh Longowal, on 13 March 2018 urged all Sikhs to follow the current Nanakshahi calendar; the previous SGPC President before Longowal, Prof. Kirpal Singh Badungar, tried to appeal the Akal Takht to celebrate the birthday of Guru Gobind Singh on 23 Poh as per the original Nanakshahi calendar, but the appeal was denied; the PSGPC and a majority of the other gurdwara managements across the world are opposing the modified version of the calendar citing that the SGPC reverted to the Bikrami calendar. They argue that in the Bikrami calendar, dates of many gurpurbs coincide, thereby creating confusion among the Sikh Panth. According to Ahaluwalia, the Nanakshahi calendar goes against the use of lunar Bikrami dates by the Gurus themselves and is contradictory, it begins with the year of birth of
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