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
1st millennium BC
The 1st millennium BC is the period of time between from the year 1000 BC to 1 BC. It encompasses the Iron Age in the Old World and sees the transition from the Ancient Near East to classical antiquity. World population doubled over the course of the millennium, from about 100 million to about 200–250 million; the Neo-Assyrian Empire dominates the Near East in the early centuries of the millennium, supplanted by the Achaemenid Empire in the 6th century. Ancient Egypt is in decline, falls to the Achaemenids in 525 BC. In Greece, Classical Antiquity begins with the colonization of Magna Graecia and peaks with the conquest of the Achaemenids and the subsequent flourishing of Hellenistic civilization; the Roman Republic supplants the Etruscans and the Carthaginians. The close of the millennium sees the rise of the Roman Empire; the early Celts dominate Central Europe. In East Africa, the Nubian Empire and Aksum arise. In South Asia, the Vedic civilization blends into the Maurya Empire; the Scythians dominate Central Asia.
In China, the Spring and Autumn period sees the rise of Confucianism. Towards the close of the millennium, the Han Dynasty extends Chinese power towards Central Asia, where it borders on Indo-Greek and Iranian states. Japan is in the Yayoi period; the Maya civilization rises in Mesoamerica. The first millennium BC is the formative period of the classical world religions, with the development of early Judaism Zoroastrianism in the Near East, Vedic religion and Vedanta and Buddhism in India. Early literature develops in Greek, Hebrew, Sanskrit and Chinese; the term Axial Age, coined by Karl Jaspers, is intended to express the crucial importance of the period of c. the 8th to 2nd centuries BC in world history. World population more than doubled over the course of the millennium, from about an estimated 50–100 million to an estimated 170–300 million. Close to 90% of world population at the end of the first millennium BC lived in the Iron Age civilizations of the Old World; the population of the Americas was below 20 million, concentrated in Mesoamerica.
The population of Oceania was less than one million people. 10th century BC Near East: Neo-Assyrian Empire Near East: Shoshenq I invades Canaan Aegean: Helladic period ends 9th century BC Egypt: 872 BC: Nile floods the Temple of Luxor Egypt: 836 BC: Civil war in Egypt North Africa: 814 BC: Carthage founded China: 841 BCndash. Greece: Archaic Greece, Greek alphabet Greece: Homer 776 BC: Greece: First Olympiad 753 BC: Europe: foundation of Rome 7th century BC 671 BC: Assyrian conquest of Egypt Near East: 631 BC: Death of Ashurbanipal, decline of the Assyrian Empire 6th century BC Egypt: 592 BC: Psamtik II sacks Napata Sudan: Aspelta moves the Kushite capital to Meroe Near East: 539 BC: Achaemenid conquest of Babylon under Cyrus the Great South Asia: Śramaṇa movement and "second urbanisation" South Asia: Early Buddhism Europe: 509 BC: Roman Republic 5th century BC China: 479 BC: death of Confucius China: 476 BC: Warring States period China: 486 BC: Grand Canal construction begins Near East: Second Temple Judaism, redaction of the Hebrew Bible Greece: beginning of the classical period.
Greece: Greco-Persian Wars Greece: 440 BC: Herodotus' Histories Greece: 431 BC: Peloponnesian War Oceania: Austronesian expansion reaches Western Polynesia 4th century BC Greece: 395 BC: Corinthian War Egypt: 343 BC: Achaemenid conquest Greece/Asia/Egypt: 330s BC: conquests of Alexander the Great, end of the Achaemenid Empire, Macedonian Empire, beginning of the Hellenistic period South Asia: Mauryan Empire 3rd century BC China: Qin Unified China China: 206 BC: Han Dynasty South Asia: 261 BC: Kalinga war Rome: Roman expansion in Italy Rome/Carthage: Punic Wars 264 BC: First Punic War 218 BC Second Punic War 2nd century BC Rome/Carthage: 149 BC Third Punic War, Roman province of Africa Rome/Greece: 146 BC Battle of Corinth, beginning of the Roman era South Asia: 185 BC: Fall of the Maurya Empire China: Confucianism became the state ideology of China 1st century BC China: 91 BC: Records of the Grand Historian finished Rome/Europe: 58-50 BC Gallic Wars Rome: 32/30 BC: Final War of the Roman Republic Rome/Egypt: 31 BC: Roman conquest of Egypt Rome/Europe/West Asia/Africa: 27 BC: Roman Empire Some of the central figures of the Axial Age are legendary or semi-legendary, with no contemporary written records available RulersChina: Dynasties in Chinese history, List of Chinese monarchs Egypt: Third Intermediate Period of Egypt Carthage: List of monarchs of Carthage Assyrian Empire: List of Assyrian kings Babylonia: Neo-Babylonian_dynasty Canaan / Biblical Levant: Kings of Israel and Judah Achaemenid Persia: List of monarchs of Persia Kingdom of Kush: List of monarchs of Kush Classical Greece: Monarchs: List of kings of Sparta, Thirty Tyrants Athenian democracy: Pericles Macedon: List of ancient Macedonians, Argead dynasty Hellenistic period: Ptolemaic Dynasty, Antigonid dynasty, Hasmonean dynasty Rome: kings of Rome, List of Roman consuls Parthian Empire: List of Parthian kings India: List of Indian monarchsReligion, p
3rd century BC
The 3rd century BC started the first day of 300 BC and ended the last day of 201 BC. It is considered part of epoch, or historical period. In the Mediterranean Basin, the first few decades of this century were characterized by a balance of power between the Greek Hellenistic kingdoms in the east, the great mercantile power of Carthage in the west; this balance was shattered when conflict arose between the Roman Republic. In the following decades, the Carthaginian Republic was first humbled and destroyed by the Romans in the First and Second Punic Wars. Following the Second Punic War, Rome became the most important power in the western Mediterranean. In the eastern Mediterranean, the Seleucid Empire and Ptolemaic Kingdom, successor states to the empire of Alexander the Great, fought a series of Syrian Wars for control over the Levant. In mainland Greece, the short-lived Antipatrid dynasty of Macedon was overthrown and replaced by the Antigonid dynasty in 294 BC, a royal house that would dominate the affairs of Hellenistic Greece for a century until the stalemate of the First Macedonian War against Rome.
Macedon would lose the Cretan War against the Greek city-state of Rhodes and its allies. In India, Ashoka ruled the Maurya Empire; the Pandya and Chera dynasties of the classical age flourished in the ancient Tamil country. The Warring States period in China drew to a close, with Qin Shi Huang conquering the six other nation-states and establishing the short-lived Qin dynasty, the first empire of China, followed in the same century by the long-lasting Han dynasty. However, a brief interregnum and civil war existed between the Qin and Han periods known as the Chu-Han contention, lasting until 202 BC with the ultimate victory of Liu Bang over Xiang Yu; the Protohistoric Period began in the Korean peninsula. In the following century the Chinese Han dynasty would conquer the Gojoseon kingdom of northern Korea; the Xiongnu were at the height of their power in Mongolia. They defeated the Han Chinese at the Battle of Baideng in 200 BC, marking the beginning of the forced Heqin tributary agreement and marriage alliance that would last several decades.
299 BC: The Samnites, seizing their chance when Rome is engaged on the Lombard plain, start the Third Samnite War with a collection of mercenaries from Gaul and Sabine and Etruscan allies to help them. 298 BC: The Samnites defeat the Romans under Lucius Cornelius Scipio Barbatus in the Battle of Camerinum, the first battle of the Third Samnite War. 294 BC: Antipater II of Macedon is killed by Lysimachus, allowing Demetrius I to become king of Macedonia, thus ending the Antipatrid dynasty's control over Hellenistic Greece and ushering in a period of rule by the Antigonid dynasty. 293 BC: The Chinese State of Qin reduced the threat of the State of Wei and the State of Han with the Qin victory in the Battle of Yique. Roman armies penetrate into the heart of the Samnite territory and capture the Samnite cities of Taurasia, Bovianum Vetus and Aufidena. Agathocles, king of Syracuse, assists the Italian Greeks against the Bruttians. Bindusara succeeds his father Chandragupta Maurya as emperor of the Mauryan Empire.
The Epi-Olmec culture forms as a successor civilization to the Olmecs in Mesoamerica. 285 BC: The Pharos of Alexandria is completed. 281 BC: Antiochus I Soter, on the assassination of his father Seleucus becomes emperor of the Seleucid empire. 281 BC: Achaean League founded in Greece. 280 BC: King Pyrrhus of Epirus invades Italy in an attempt to subjugate the Romans and bring Italy under a new empire ruled by himself. 280 BC: Construction of the Colossus of Rhodes is completed. 279 BC: Singidunum and Taurunum, today's Belgrade and Zemun, are founded by Scordisci Celts. After failing to decisively defeat the Romans, Pyrrhus of Epirus withdraws from Italy. Gallic migration to Macedon and Galatia. During the Gallic invasion of Greece, the Macedonian king Ptolemy Keraunos is killed in battle by the forces of the Celtic ruler Bolgios. However, both he and Brennus are driven out of Macedonian territory by Sosthenes of Macedon. 277 BC: in the Battle of Lysimachia, the invasion by Gauls is defeated by Antigonus II of Macedon.
274 BC: the First Syrian War erupts between Antiochus I Soter of the Seleucid dynasty and Ptolemy II Philadelphus of the Ptolemaic dynasty over control of Syria and southern Anatolia. 273 BC – 232 BC: Ashoka the Great ruled the Maurya Empire. 265 BC: Kalinga War takes place between Ashoka the Great and the kingdom of Kalinga. 264 BC: First Punic War breaks out between the Carthaginian Empire and the Roman Republic. 261 BC: Antiochus II Theos, 2nd son, at the death of his father becomes emperor of the Seleucid empire. 260 BC: Battle of Changping between the State of Qin and the State of Zhao in China. 260 BC: Ashoka inscribes the Edicts of Ashoka. 258 BC: An Dương Vương overthrows the Hồng Bàng Dynasty in Viet Nam. 257 BC: Thục Dynasty takes over Vietnam. 246 BC: The death of Antiochus II sparks the Third Syrian War. Expansion of the Achaean League. 241 BC: First Punic War ends in Carthaginian defeat. Rome demands large reparations, annexes Sicily and Corsica. 240 BC: On May 15, Chinese mathematicians observed and recorded the passage of the Halley's Comet.
230 BC: The Chinese Qin State conquers Han. 230 BC: Simuka declares independence from Mauryan rule and establishes the Satavahana Empire. 229 BC: The First Illyrian War ends with a Roman victory. 229 BC: Last tyrants on the Peloponnese abdicate, Argos joins the Achaean League, Athens liberated from Macedonian garrison. 227 BC: The attempted assassination of Ying Zheng, king
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 Ethiopian calendar or Eritrean calendar is the principal calendar used in Ethiopia and serves as the liturgical year for Christians in Eritrea and Ethiopia belonging to the Eritrean Orthodox Tewahedo Church, Ethiopian Orthodox Tewahedo Church, Eastern Catholic Churches, the Coptic Orthodox Church of Alexandria, Ethiopian-Eritrean Evangelicalism. It is a solar calendar which in turn derives from the Egyptian calendar, but like the Julian calendar, it adds a leap day every four years without exception, begins the year on August 29 or August 30 in the Julian calendar. A gap of 7–8 years between the Ethiopian and Gregorian calendars results from an alternative calculation in determining the date of the Annunciation. Like the Coptic calendar, the Ethiopic calendar has 12 months of 30 days plus 5 or 6 epagomenal days, which comprise a thirteenth month; the Ethiopian months begin on the same days as those of the Coptic calendar, but their names are in Ge'ez. A 6th epagomenal day is added every 4 years, without exception, on August 29 of the Julian calendar, 6 months before the corresponding Julian leap day.
Thus the first day of the Ethiopian year, 1 Mäskäräm, for years between 1900 and 2099, is September 11. However, it falls on September 12 in years before the Gregorian leap year. Enkutatash is the word for the Ethiopian New Year in Amharic, the official language of Ethiopia, while it is called Ri'se Awde Amet in Ge'ez, the term preferred by the Ethiopian & Eritrean Orthodox Tewahedo Churchs, it occurs on September 11th in the Gregorian Calendar. The Ethiopian Calendar Year 1998 Amätä Məhrät began on the Gregorian Calendar Year on September 11th, 2005. However, the Ethiopian Years 1992 and 1996 began on the Gregorian Dates of'September 12th 1999' and'2003' respectively; this date correspondence applies for the Gregorian years 1900 to 2099. The Ethiopian leap year is every four without exception, while Gregorian centurial years are only leap years when divisible by 400; as the Gregorian year 2000 is a leap year, the current correspondence lasts two centuries instead. The start of the Ethiopian year falls on August 30th.
This date corresponds to the Old-Style Julian Calendar. This deviation between the Julian and the Gregorian Calendar will increase with the passing of the time. You can observe the real start date in the future centuries in a Gregorian to Ethiopian Date Converter. To indicate the year and followers of the Eritrean churches today use the Incarnation Era, which dates from the Annunciation or Incarnation of Jesus on March 25, AD 9, as calculated by Annianus of Alexandria c. 400. Meanwhile, Europeans adopted the calculations made by Dionysius Exiguus in AD 525 instead, which placed the Annunciation 8 years earlier than had Annianus; this causes the Ethiopian year number to be 8 years less than the Gregorian year number from January 1 until September 10 or 11 7 years less for the remainder of the Gregorian year. In the past, a number of other eras for numbering years were widely used in Ethiopia and the Kingdom of Aksum; the most important era – once used by the Eastern Christianity, still used by the Coptic Orthodox Church of Alexandria – was the Era of Martyrs known as the Diocletian Era, or the era of Diocletian and the Martyrs, whose first year began on August 29, 284.
Respective to the Gregorian and Julian New Year's Days, 31⁄2 to 4 months the difference between the Era of Martyrs and the Anni Domini is 285 years. This is because in AD 525, Dionysius Exiguus decided to add 15 Metonic cycles to the existing 13 Metonic cycles of the Diocletian Era to obtain an entire 532 year medieval Easter cycle, whose first cycle ended with the year Era of Martyrs 247 equal to year DXXXI, it is because 532 is the product of the Metonic cycle of 19 years and the solar cycle of 28 years. Around AD 400, an Alexandrine monk called Panodoros fixed the Alexandrian Era, the date of creation, on 29 August 5493 BC. After the 6th century AD, the era was used by Ethiopian chronologists; the twelfth 532 year-cycle of this era began on 29 August AD 360, so 4×19 years after the Era of Martyrs. Bishop Anianos preferred the Annunciation style as 25 March, thus he shifted the Panodoros era by about six months, to begin on 25 March 5492 BC. In the Ethiopian calendar this was equivalent to 15 Magabit 5501 B.
C.. The Anno Mundi era remained in usage until the late 19th century; the 4 year leap-year cycle is associated with the four Evangelists: the first year after an Ethiopian leap year is named the John-year, followed by the Matthew-year, the Mark-year. The year with the 6th epagomenal day is traditionally designated as the Luke-year. There are no exceptions to the 4 year leap-year cycle, like the Julian calendar but unlike the Gregorian calendar; these dates are valid only from March 1900 to February 2100. This is because 1900 and 2100 are not leap years in the Gregorian calendar, while they are still leap year
The majority of Egyptologists agree on the outline and many details of the chronology of Ancient Egypt. This scholarly consensus is the so-called Conventional Egyptian chronology, which places the beginning of the Old Kingdom in the 27th century BC, the beginning of the Middle Kingdom in the 21st century BC and the beginning of the New Kingdom in the mid-16th century BC. Despite this consensus, disagreements remain within the scholarly community, resulting in variant chronologies diverging by about 300 years for the Early Dynastic Period, up to 30 years in the New Kingdom, a few years in the Late Period. In addition, there are a number of "alternative chronologies" outside scholarly consensus, such as the "New Chronology" proposed in the 1990s, which lowers New Kingdom dates by as much as 350 years, or the "Glasgow Chronology", which lowers New Kingdom dates by as much as 500 years. Scholarly consensus on the general outline of the conventional chronology current in Egyptology has not fluctuated much over the last 100 years.
For the Old Kingdom, consensus fluctuates by as much as a few centuries, but for the Middle and New Kingdoms, it has been stable to within a few decades. This is illustrated by comparing the chronology as given by two Egyptologists, the first writing in 1906, the second in 2000; the disparities between the two sets of dates result from additional discoveries and refined understanding of the still incomplete source evidence. For example, Breasted adds a ruler in the Twentieth dynasty that further research showed did not exist. Following Manetho, Breasted believed all the dynasties were sequential, whereas it is now known that several existed at the same time; these revisions have resulted in a lowering of the conventional chronology by up to 400 years at the beginning of Dynasty I. Forming the backbone of Egyptian chronology are the regnal years as recorded in Ancient Egyptian king lists. Surviving king lists are either comprehensive but have significant gaps in their text, or are textually complete but fail to provide a complete list of rulers for a short period of Egyptian history.
The situation is further complicated by occasional conflicting information on the same regnal period from different versions of the same text. Regnal periods have to be pieced together from inscriptions, which will give a date in the form of the regnal year of the ruling pharaoh, yet this only provides a minimum length of that reign and may or may not include any coregencies with a predecessor or successor. In addition, some Egyptian dynasties overlapped, with different pharaohs ruling in different regions at the same time, rather than serially. Not knowing whether monarchies were simultaneous or sequential results in differing chronological interpretations. Where the total number of regnal years for a given ruler is not known, Egyptologists have identified two indicators to deduce that total number: for the Old Kingdom, the number of cattle censuses. A number of Old Kingdom inscriptions allude to a periodic census of cattle, which experts at first believed took place every second year. However, further research has shown that these censuses were sometimes taken in consecutive years, or after two or more years had passed.
The Sed festival was celebrated on the thirtieth anniversary of a pharaoh's ascension, thus rulers who recorded celebrating one could be assumed to have ruled at least 30 years. However, once again, this may not have been standard practice in all cases. In the early days of Egyptology, the compilation of regnal periods was hampered by a profound biblical bias on the part of Egyptologists; this was most pervasive before the mid 19th century, when Manetho's figures were recognized as conflicting with biblical chronology, based on Old Testament references to Egypt. In the 20th century, such biblical bias has been confined to alternative chronologies outside the scholarly mainstream. A useful way to work around these gaps in knowledge is to find chronological synchronisms, which can lead to a precise date. Over the past decades, a number of these have been found, although they are of varying degrees of usefulness and reliability. Seriation, i.e. archeological sequences. This does not fix a person or event to a specific year, but establishing a sequence of events can provide indirect evidence to provide or support a precise date.
For example, some inscribed stone vessels of the rulers of the first two dynasties were collected and deposited in storage galleries beneath and sealed off when the Step Pyramid of Djoser, a Pharaoh of the Third Dynasty, was built. Another example are blocks from the Old Kingdom bearing the names of several kings, which were reused in the construction of Middle Kingdom pyramid-temples at Lisht in the structures of Amenemhat I; the third pylon at Karnak, built by Amenhotep III contained as "fill" material from the kiosk of Sesostris I, along with various stelae of the Second Intermediate Period and the Eighteenth Dynasty of the New Kingdom. Synchronisms with other chronologies, the most important of these being with the Assyrian and Babylonian chronologies, but synchronisms with the Hittites, ancient Palestine, in the final period with ancient Greece, are used; the earliest such synchronism is in the 18th century
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