The traditional China calendar, or Former Calendar, Traditional Calendar or Lunar Calendar, is a lunisolar calendar which reckons years and days according to astronomical phenomena. It is defined by GB/T 33661-2017, "Calculation and promulgation of the Chinese calendar", issued by the Standardisation Administration of China on 12 May 2017. Although modern day China uses the Gregorian calendar, the traditional Chinese calendar governs holidays in China and in overseas Chinese communities, it lists the dates of traditional Chinese holidays and guides people in selecting auspicious days for weddings, moving, or starting a business. Like Chinese characters, variants of this calendar are used in different parts of the Chinese cultural sphere. Korea and the Ryukyu Islands adopted the calendar, it evolved into Korean and Ryukyuan calendars; the main difference from the traditional Chinese calendar is the use of different meridians, which leads to some astronomical events—and calendar events based on them—falling on different dates.
The traditional Japanese calendar derived from the Chinese calendar, but its official use in Japan was abolished in 1873 as part of reforms after the Meiji Restoration. Calendars in Mongolia and Tibet have absorbed elements of the traditional Chinese calendar, but are not direct descendants of it. Days begin and end at midnight, months begin on the day of the new moon. Years begin on the second new moon after the winter solstice. Solar terms govern the end of each month. Written versions in ancient China included stems and branches of the year and the names of each month, including leap months as needed. Characters indicated whether a month was short; the traditional Chinese calendar was developed between 771 and 476 BC, during the Spring and Autumn period of the Eastern Zhou dynasty. Before the Zhou dynasty, solar calendars were used. One version of the solar calendar is the five-elements calendar. A 365-day year was divided into five phases of 73 days, with each phase corresponding to a Day 1 Wu Xing element.
A phase began followed by six 12-day weeks. Each phase consisted of two three-week months. Years began followed by a bǐngzǐ day and a 72-day fire phase. Other days were tracked using the Yellow River Map. Another version is a four-quarters calendar. Weeks were ten days long, with one month consisting of three weeks. A year had 12 months, with a ten-day week intercalated in summer as needed to keep up with the tropical year; the 10 Heavenly Stems and 12 Earthly Branches were used to mark days. A third version is the balanced calendar. A year was 365.25 days, a month was 29.5 days. After every 16th month, a half-month was intercalated. According to oracle bone records, the Shang dynasty calendar was a balanced calendar with 12 to 14 months in a year; the first lunisolar calendar was the Zhou calendar, introduced under the Zhou dynasty. This calendar set the beginning of the year at the day of the new moon before the winter solstice, it set the shàngyuán as the winter solstice of a dīngsì year, making the year it was introduced around 2,758,130.
Several competing lunisolar calendars were introduced by states fighting Zhou control during the Warring States period. The state of Lu issued its own Lu calendar. Jin issued the Xia calendar in AD 102, with a year beginning on the day of the new moon nearest the March equinox. Qin issued the Zhuanxu calendar, with a year beginning on the day of the new moon nearest the winter solstice. Song's Yin calendar began its year on the day of the new moon after the winter solstice; these calendars are known as the six ancient calendars, or quarter-remainder calendars, since all calculate a year as 365 1⁄4 days long. Months begin on the day of the new moon, a year has 12 or 13 months. Intercalary months are added to the end of the year; the Qiang and Dai calendars are modern versions of the Zhuanxu calendar, used by mountain peoples. After Qin Shi Huang unified China under the Qin dynasty in 221 BC, the Qin calendar was introduced, it followed most of the rules governing the Zhuanxu calendar, but the month order was that of the Xia calendar.
The intercalary month, known as the second Jiǔyuè, was placed at the end of the year. The Qin calendar was used into the Han dynasty. Emperor Wu of Han r. 141 – 87 BC introduced reforms halfway through his reign. His Taichu Calendar defined a solar year as 365 385⁄1539 days, the lunar month was 29 43⁄81 days; this calendar introduced the 24 solar terms. Solar terms were paired, with the 12 combined periods known as climate terms; the first solar term of the period was known as a pre-climate, the second was a mid-climate. Months were named for the mid-climat
The 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
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 Javanese calendar is the calendar of the Javanese people. It is used concurrently with the Gregorian calendar and the Islamic calendar; the Gregorian calendar is the official calendar of the Republic of Indonesia and civil society, while the Islamic calendar is used by Muslims and the Indonesian government for religious worship and deciding relevant Islamic holidays. The Javanese calendar is used by the main ethnicities of Java island—that is, the Javanese and Sundanese people—primarily as a cultural icon and identifier, as a maintained tradition of antiquity; the Javanese calendar is used for cultural and spiritual purposes. The current system of the Javanese calendar was inaugurated by Sultan Agung of Mataram in the Gregorian year 1633 CE. Prior to this, the Javanese had used the Hindu calendar, which begins in 78 CE and uses the solar cycle for calculating time. Sultan Agung's calendar retained the Saka calendar year system of counting, but differs by using the same lunar year measurement system as the Islamic calendar, rather than the solar year.
The Javanese calendar is referred to by its Latin name Anno Javanico or AJ. The Javanese calendar contains multiple, overlapping measurements of times, called "cycles"; these include: the native five-day week, called Pasaran the common Gregorian and Islamic seven-day week the Solar month, called Mangsa the Lunar month, called Wulan the lunar year, or Tahun the octo-ennia cycles, or Windu the 120-year cycle of 15 Windu, called Kurup Days in the Javanese calendar, like the Islamic calendar, begin at sunset. Traditionally, Javanese people do not divide the night into hours, but rather into phases; the division of a day and night are: The native Javanese system groups days into a five-day week called Pasaran, unlike most calendars that uses a seven-day week. The name, pasaran, is derived from the root word pasar, but still today, Javanese villagers gather communally at local markets to meet, engage in commerce, buy and sell farm produce, cooked foods, home industry crafted items and so on. John Crawfurd suggested that the length of the weekly cycle is related to the number of fingers on the hand, that itinerant merchants would rotate their visits to different villages according to a five-day "roster".
The days of the cycle each have two names, as the Javanese language has distinct vocabulary associated with two different registers of politeness: ngoko and krama. The krama names for the days, second in the list, are much less common. ꦊꦒꦶ – ꦩꦤꦶꦱ꧀ ꦥꦲꦶꦁ – ꦥꦲꦶꦠ꧀ ꦥꦺꦴꦤ꧀ – ꦥꦼꦠꦏ꧀ ꦮꦒꦺ – ꦕꦼꦩꦺꦁ ꦏ꧀ꦭꦶꦮꦺꦴꦤ꧀ – ꦲꦱꦶꦃ The origin of the names is unclear, their etymology remains obscure. The names may be derived from indigenous gods, like the European and Asian names for days of the week. An ancient Javanese manuscript illustrates the week with five human figures: a man seizing a suppliant by the hair, a woman holding a horn to receive an offering, a man pointing a drawn sword at another, a woman holding agricultural produce, a man holding a spear leading a bull. Additionally, Javanese consider these days' names to have a mystical relation to colors and cardinal direction: Legi: white and East Pahing: red and South Pon: yellow and West Wage: black and North Kliwon: blurred colors/focus and'center'. Most Markets no longer operate under this traditional Pasaran cycle, instead pragmatically remaining open every day of the Gregorian week.
However many markets in Java still retain traditional names that indicated that once the markets only operated on certain Pasaran days, such as Pasar Legi, or Pasar Kliwon. Some markets in small or medium size locations will be much busier on the Pasaran day than on the other days. On the market's name day itinerate sellers appear selling such things as livestock and other products that are either less purchased or are more expensive; this allows a smaller number of these merchants to service a much larger area much as in bygone days. Javanese astrological belief dictates that an individual’s characteristics and destiny are attributable to the combination of the Pasaran day and the "common" weekday of the Islamic calendar on that person's birthday. Javanese people find great interest in the astrological interpretations of this combination, called the Wetonan cycle; the seven-day-long week cycle is derived from the Islamic calendar, adopted following the spread of Islam throughout the Indonesian archipelago.
The names of the days of the week in Javanese are derived from their Arabic counterparts, namely: These two-week systems occur concurrently. This combination forms the Wetonan cycle; the Wetonan cycle superimposes the five-day Pasaran cycle with the seven-day week cycle. Each Wetonan cycle lasts for 35 days. An example of Wetonan cycle: From the example above, the Weton for Tuesday May 6, 2008 would be read as Selasa Wage; the Wetonan cycle is important for divinatory systems, important celebrations, rites of passage. Commemorations and events are held on days considered to be auspicious. An prominent example, still taught in primary schools, is that the Weton for the Proclamation of Indonesian Independence on 17 August 1945 took place on Jumat Legi. Therefore, Jumat Legi is considered an important night for pilgrimage. There are taboos
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 Berber calendar is the agricultural calendar traditionally used by Berbers. It is known as the fellaḥi; the calendar is utilized to regulate the seasonal agricultural works. The Islamic calendar, a lunar calendar, is not suited for agriculture because it does not relate to seasonal cycles. In other parts of the Islamic world either Iranian solar calendars, the Coptic calendar, the Rumi calendar, or other calendars based on the Julian calendar, were used before the introduction of the Gregorian calendar; the current Berber calendar is a legacy of the Roman province of Mauretania Caesariensis and the Roman province of Africa, as it is a surviving form of the Julian calendar. The latter calendar was used in Europe before the adoption of the Gregorian calendar, with month names derived from Latin. Berber populations used various indigenous calendars, such as that of the Guanche autochthones of the Canary Islands; however little is known of these ancient calendrical systems. The agricultural Berber calendar still in use is certainly derived from the Julian calendar, introduced in the Roman province of Africa at the time of Roman domination.
The names of the months of this calendar are derived from the corresponding Latin names and races of the Roman calendar denominations of Kalends and Ides exist: El Qabisi, an Islamic jurisconsult by Kairawan who lived in the 11th century, condemned the custom of celebrating "pagans'" festivals and cited, among traditional habits of North Africa, that of observing January Qalandas. The length of the year and of the individual months is the same as in the Julian calendar: three years of 365 days followed by a leap year of 366, without exceptions, 30- and 31-day months, except for the second one that has 28 days; the only slight discrepancy lies in that the extra day in leap years is not added at the end of February, but at the end of the year. This means that the beginning of the year corresponds to the 14th day of January in the Gregorian calendar, which coincides with the offset accumulated during the centuries between astronomical dates and the Julian calendar. In addition to the subdivision by months, within the traditional agricultural calendar there are other partitions, by "seasons" or by "strong periods", characterized by particular festivals and celebrations.
Not all the four seasons have retained a Berber denomination: the words for spring and autumn are used everywhere, more sparingly the winter and, among northern Berbers, the Berber name for the autumn has been preserved only in Jebel Nafusa. Spring tafsut – Begins on 15 furar Summer anebdu – Begins on 17 mayu Autumn amwal / aməwan ( – Begins on 17 ghusht Winter tagrest - Begins on 16 numbír An interesting element is the existing opposition between two 40-day terms, one representing the coldest part of winter and one the hottest period of summer; the coldest period is made up by 20 "white nights", from 12 to 31 dujamber, 20 "black nights", beginning on the first day of yennayer, corresponding to the Gregorian 14 January. The first day of the year is celebrated in various ways in the different parts of North Africa. A widespread tradition is a meal with particular foods. In some regions, it is marked by the sacrifice of an animal. In Algeria, such a holiday is celebrated by many people who don't use the Berber calendar in daily life.
A characteristic trait of this festivity, which blurs with the Islamic Day of Ashura, is the presence, in many regions, of ritual invocations with formulas like bennayu, babiyyanu, bu-ini, etc. Such expressions, according to many scholars, may be derived from of the ancient bonus annus wishes. A curious aspect of the Yennayer celebrations concerns the date of New Year's Day. Though once this anniversary fell everywhere on 14 January, because of a mistake introduced by some Berber cultural associations active in recovering customs on the verge of extinction, at present in a wide part of Algeria it is common opinion that the date of "Berber New Year's Day" is 12 January and not the 14th; the celebration at the 12, two days before the traditional one, it had been explicitly signaled in the city of Oran. El Azara is the period of the year extending, according to the Berber calendar, from 3 to 13 February and known by a climate sometimes hot, sometimes cold. Before the cold ends and spring begins there is a period of the year, feared.
It consists of ten days straddling the months of furar and mars, it is characterised by strong winds. It is said that, during this term, one should suspend many activities, should not marry nor go out during the night, leaving instead full scope to mysterious powers, which in that period are active and celebrate their weddings. Due to a linguistic taboo, in Djerba these creatures are called imbarken, i.e. "the blessed ones", whence this period takes its name. Jamrat el Ma, "embers of the sea", 27 February, is marked by a rise in sea temperature. Jamrat el Trab, "land embers" in English, is the period from 6 to 10 March and known to be marked by a mixture of heavy rain and sunny weather. Jamrat or coal is a term used t
The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin alphabet. Roman numerals, as used today, employ seven symbols, each with a fixed integer value, as follows: The use of Roman numerals continued long after the decline of the Roman Empire. From the 14th century on, Roman numerals began to be replaced in most contexts by the more convenient Arabic numerals; the original pattern for Roman numerals used the symbols I, V, X as simple tally marks. Each marker for 1 added a unit value up to 5, was added to to make the numbers from 6 to 9: I, II, III, IIII, V, VI, VII, VIII, VIIII, X; the numerals for 4 and 9 proved problematic, are replaced with IV and IX. This feature of Roman numerals is called subtractive notation; the numbers from 1 to 10 are expressed in Roman numerals as follows: I, II, III, IV, V, VI, VII, VIII, IX, X.
The system being decimal and hundreds follow the same underlying pattern. This is the key to understanding Roman numerals: Thus 10 to 100: X, XX, XXX, XL, L, LX, LXX, LXXX, XC, C. Note that 40 and 90 follow the same subtractive pattern as 4 and 9, avoiding the confusing XXXX. 100 to 1000: C, CC, CCC, CD, D, DC, DCC, DCCC, CM, M. Again - 400 and 900 follow the standard subtractive pattern, avoiding CCCC. In the absence of standard symbols for 5,000 and 10,000 the pattern breaks down at this point - in modern usage M is repeated up to three times; the Romans had several ways to indicate larger numbers, but for practical purposes Roman Numerals for numbers larger than 3,999 are if used nowadays, this suffices. M, MM, MMM. Many numbers include hundreds and tens; the Roman numeral system being decimal, each power of ten is added in descending sequence from left to right, as with Arabic numerals. For example: 39 = "Thirty nine" = XXXIX. 246 = "Two hundred and forty six" = CCXLVI. 421 = "Four hundred and twenty one" = CDXXI.
As each power of ten has its own notation there is no need for place keeping zeros, so "missing places" are ignored, as in Latin speech, thus: 160 = "One hundred and sixty" = CLX 207 = "Two hundred and seven" = CCVII 1066 = "A thousand and sixty six" = MLXVI. Roman numerals for large numbers are nowadays seen in the form of year numbers, as in these examples: 1776 = MDCCLXXVI. 1954 = MCMLIV 1990 = MCMXC. 2014 = MMXIV (the year of the games of the XXII Olympic Winter Games The current year is MMXIX. The "standard" forms described above reflect typical modern usage rather than an unchanging and universally accepted convention. Usage in ancient Rome varied and remained inconsistent in medieval times. There is still no official "binding" standard, which makes the elaborate "rules" used in some sources to distinguish between "correct" and "incorrect" forms problematic. "Classical" inscriptions not infrequently use IIII for "4" instead of IV. Other "non-subtractive" forms, such as VIIII for IX, are sometimes seen, although they are less common.
On the numbered gates to the colosseum, for instance, IV is systematically avoided in favour of IIII, but other "subtractives" apply, so that gate 44 is labelled XLIIII. Isaac Asimov speculates that the use of "IV", as the initial letters of "IVPITER" may have been felt to have been impious in this context. Clock faces that use Roman numerals show IIII for four o'clock but IX for nine o'clock, a practice that goes back to early clocks such as the Wells Cathedral clock of the late 14th century. However, this is far from universal: for example, the clock on the Palace of Westminster, Big Ben, uses a "normal" IV. XIIX or IIXX are sometimes used for "18" instead of XVIII; the Latin word for "eighteen" is rendered as the equivalent of "two less than twenty" which may be the source of this usage. The standard forms for 98 and 99 are XCVIII and XCIX, as described in the "decimal pattern" section above, but these numbers are rendered as IIC and IC originally from the Latin duodecentum and undecentum.
Sometimes V and L are not used, with instances such as IIIIII and XXXXXX rather than VI or LX. Most non-standard numerals other than those described above - such as VXL for 45, instead of the standard XLV are modern and may be due to error rather than being genuine variant usage. In the early years of the 20th century, different representations of 900 appeared in several inscribed dates. For instance, 1910 is shown on Admiralty Arch, London, as MDCCCCX rather than MCMX, while on the north entrance to the Saint Louis Art Museum, 1903 is inscribed as MDCDIII rather than MCMIII. Although Roman numerals came to be written with letters