24-hour analog dial
Clocks and watches with a 24-hour analog dial have an hour hand that makes one complete revolution, 360°, in a day. The more familiar 12-hour analog dial has an hour hand. Twenty-four-hour analog clocks and watches are used today by pilots and the military, are sometimes preferred because of the unambiguous representation of a whole day at a time. Note that this definition refers to the use of a complete circular dial to represent a 24-hour day. Using the numbers from 0 to 23 to mark the day is the 24-hour clock system. Sundials use 24-hour analog dials—the shadow traces a path that repeats once per day. Many sundials are marked with the double-XII or double-12 system, in which the numbers I to XII are used twice, once for the morning hours, once for the afternoon and evening hours. So VI appears twice on many dials, once near sunrise and once near sunset. Modern 24-hour analog dials—other than sundials—are always marked with 24 numbers or hour marks around the edge, using the 24-hour clock system.
These dials do not need to indicate AM or PM. The ancient Egyptians divided the day into 24 hours. There are diagrams of circles divided into 24 sections in the astronomical ceiling in the tomb of Senemut. Sundials use all of the 24-hour dial, because they show the position of the sun in the sky. Sometimes, for aesthetic rather than practical reasons, all the 24 hour marks are shown. Medieval clocks used the 24-hour analog dial, influenced by the widespread example of the astrolabe. In Northern Europe, the double-XII system was preferred: two sets of the Roman numerals I to XII were used, one on the left side for the night and morning hours, another set on the right side of the dial to represent the afternoon and evening hours. In Italy, the numbers from 1 to 24 were used, leading to the widespread use of the 24-hour system in that country. On Italian clocks, the I was shown at the right side of the dial, rather than the top; this reflects the influence of the Italian timekeeping system, which started counting the hours of the day at sunset or twilight.
In northern Europe, the double XII system was superseded during the 14th and 15th centuries by the single XII, leading to the widespread adoption of the 12-hour dial for popular use. The 24-hour analog dial continued to be used, but by technicians, astronomers and clockmakers. John Harrison, Thomas Tompion, Mudge built a number of clocks with 24-hour analog dials when building astronomical and nautical instruments. 24-hour dials were used on sidereal clocks. The famous Big Ben clock in London has a 24-hour dial as part of the mechanism, although it is not visible from the outside. In the 20th century, the 24-hour analog dial was adopted by radio amateurs, pilots and for military use. 24-hour analog watches and clocks are still being manufactured today, are sought after by collectors and enthusiasts. Manufacturers who make 24-hour analog watches include Glycine, Vostok, Poljot and many others; the major variation in the design of 24-hour analog dials is the location of noon. Although always opposite each other, 180° apart, noon is sometimes at the top, sometimes at the bottom.
A few rare variants left sides. There is no ambiguity. In the United States, the government and military use 24-hour clocks having noon at the bottom. A 24-hour watch is a type of watch with an hour hand; this type of watch is useful for aviators, health care professionals, members of the military. That is, anyone who uses multiple timezones; the face may be arranged in either of two ways: with noon at the top and midnight at the bottom, or else rotated 180° with midnight at the top and noon at the bottom. Multiple time zones can be displayed by having a rotating bezel; the bezel is a ring around the outside of the watch's face. When it is used, the top of the watch always represents midnight GMT; the bezel, which has hour markings, is rotated so that its numbering represents local time. So, a pilot always has GMT time available for talking to air traffic control and, when they land, only has to rotate the bezel to "set" the watch to their new local time. Glycine was the first to feature a 24-hour rotating bezel in 1953 with the Airman No.1 Pilot watch.
The design became known when Rolex designed the Rolex GMT Master II for every Pan-Am pilot. A 24-hour watch with a compass card dial can be used to determine direction when set to local noon and used in conjunction with the sun. Many digital watches can be set to show the time in 24-hour format. Akerfalk Botta Breitling Gallet Glycine watch Oris Poljot Raketa Rolex Seiko Forté Slow watch A common use for the 24-hour analog method of representing time is for showing the way the time of day depends on one's location. A globe, map, or disk can be used. George Orwell uses the 12-hour and 24-hour dials to symbolize the old and new worlds in his novel Nineteen Eighty-Four; the 12-hour dial is a relic of pre-revolutionary society, used to represent the desirable past.
A calendar is a system of organizing days for social, commercial or administrative purposes. This is done by giving names to periods of time days, weeks and years. A date is the designation of a specific day within such a system. A calendar is a physical record of such a system. A calendar can mean a list of planned events, such as a court calendar or a or chronological list of documents, such as a calendar of wills. Periods in a calendar are though not synchronised with the cycle of the sun or the moon; the most common type of pre-modern calendar was the lunisolar calendar, a lunar calendar that adds one intercalary month to remain synchronised with the solar year over the long term. The term calendar is taken from calendae, the term for the first day of the month in the Roman calendar, related to the verb calare "to call out", referring to the "calling" of the new moon when it was first seen. Latin calendarium meant "account book, register"; the Latin term was adopted in Old French as calendier and from there in Middle English as calender by the 13th century.
A calendar can be on paper or electronic device. The course of the sun and the moon are the most salient natural recurring events useful for timekeeping, thus in pre-modern societies worldwide lunation and the year were most used as time units; the Roman calendar contained remnants of a ancient pre-Etruscan 10-month solar year. The first recorded physical calendars, dependent on the development of writing in the Ancient Near East, are the Bronze Age Egyptian and Sumerian calendars. A large number of Ancient Near East calendar systems based on the Babylonian calendar date from the Iron Age, among them the calendar system of the Persian Empire, which in turn gave rise to the Zoroastrian calendar and the Hebrew calendar. A great number of Hellenic calendars developed in Classical Greece, in the Hellenistic period gave rise to both the ancient Roman calendar and to various Hindu calendars. Calendars in antiquity were lunisolar, depending on the introduction of intercalary months to align the solar and the lunar years.
This was based on observation, but there may have been early attempts to model the pattern of intercalation algorithmically, as evidenced in the fragmentary 2nd-century Coligny calendar. The Roman calendar was reformed by Julius Caesar in 45 BC; the Julian calendar was no longer dependent on the observation of the new moon but followed an algorithm of introducing a leap day every four years. This created a dissociation of the calendar month from the lunation; the Islamic calendar is based on the prohibition of intercalation by Muhammad, in Islamic tradition dated to a sermon held on 9 Dhu al-Hijjah AH 10. This resulted in an observation-based lunar calendar that shifts relative to the seasons of the solar year; the first calendar reform of the early modern era was the Gregorian calendar, introduced in 1582 based on the observation of a long-term shift between the Julian calendar and the solar year. There have been a number of modern proposals for reform of the calendar, such as the World Calendar, International Fixed Calendar, Holocene calendar, the Hanke-Henry Permanent Calendar.
Such ideas are mooted from time to time but have failed to gain traction because of the loss of continuity, massive upheaval in implementation, religious objections. A full calendar system has a different calendar date for every day, thus the week cycle is by itself not a full calendar system. The simplest calendar system just counts time periods from a reference date; this applies for Unix Time. The only possible variation is using a different reference date, in particular, one less distant in the past to make the numbers smaller. Computations in these systems are just a matter of subtraction. Other calendars have one larger units of time. Calendars that contain one level of cycles: week and weekday – this system is not common year and ordinal date within the year, e.g. the ISO 8601 ordinal date systemCalendars with two levels of cycles: year and day – most systems, including the Gregorian calendar, the Islamic calendar, the Solar Hijri calendar and the Hebrew calendar year and weekday – e.g. the ISO week dateCycles can be synchronized with periodic phenomena: Lunar calendars are synchronized to the motion of the Moon.
Solar calendars are based on perceived seasonal changes synchronized to the apparent motion of the Sun. Lunisolar calendars are based on a combination of both solar and lunar reckonings; the week cycle is an example of one, not synchronized to any external phenomenon. A calendar includes more than one type of cycle, or has both cyclic and non-cyclic elements. Most calendars incorporate more complex cycles. For example, the vast majority of them track years, months and days; the seven-day week is universal, though its use varies. It has run uninterrupted for millennia. Solar calendars assign a date to each solar day. A day may consist of the period between sunrise and sunset, with
North Korean calendar
The Democratic People's Republic of Korea calendar, DPRK calendar, or Juche calendar, named after the Juche ideology, is the system of year-numbering used in the Democratic People's Republic of Korea. The calendar borrows elements from two historical calendars used in Korea, the traditional system of Korean era names and the Gregorian calendar in which years are tied to the alleged birth of Jesus. In contrast to these two, the Juche calendar begins with the birth of the founder of the Democratic People's Republic, Kim Il-sung; the decree on the Juche calendar was adopted on 8 July 1997, on the third anniversary of the death of Kim Il-sung. The same decree designated the birth anniversary of Kim Il-sung as the Day of the Sun; the birth year of Kim Il-sung, 1912 in the Gregorian calendar, became "Juche 1" in the North Korean calendar. Thus, the year 2011 is "Juche 100", so on; this was done as a means of advancing Kim Il-sung's cult of personality. The calendar began to be implemented on the Day of the Foundation of the Republic.
On that date, news agencies, radio stations, public transport, birth certificates began to use Juche years. The year 1912 is "Juche 1" in the North Korean calendar. There are no "before Juche 1" years, years before 1912 are given numbers based on the Christian calendar only. Ranges of years that begin before 1912 and end after it are given in Christian calendar numbers only. Any other years after 1912 will be given in either Juche years only, or in Juche years and the corresponding year in the Christian calendar in parentheses. In material pertaining to relations with foreign countries, "the Juche Era and the Christian era may be used on the principles of independence and reciprocity." Example of "103" from Pyongyang University of Science and Technology. Public holidays in North Korea Minguo calendar, which has the same starting year based on the founding of the Republic of China
Rebranding is a marketing strategy in which a new name, symbol, design, or combination thereof is created for an established brand with the intention of developing a new, differentiated identity in the minds of consumers, investors and other stakeholders. This involves radical changes to a brand's logo, legal names, marketing strategy, advertising themes; such changes aim to reposition the brand/company to distance itself from negative connotations of the previous branding, or to move the brand upmarket. Rebranding can be applied to new products, mature products, or products still in development; the process can occur intentionally through a deliberate change in strategy or occur unintentionally from unplanned, emergent situations, such as a "Chapter 11 corporate restructuring," "union busting," or "bankruptcy." Rebranding can refer to a change in a company/ corporate brand that may own several sub-brands for products or companies. Rebranding has become something of a fad at the turn of the millennium, with some companies rebranding several times.
The rebranding of Philip Morris to Altria was done to help the company shed its negative image. Other rebrandings, such as the British Post Office's attempt to rebrand itself as Consignia, have proved such a failure that millions more had to be spent going back to square one. In a study of 165 cases of rebranding and Lambkin found that, whether a rebranding follows from corporate strategy or constitutes the actual marketing strategy, it aims at enhancing, transferring, and/or recreating the corporate brand equity. According to Sinclair, business the world over acknowledges the value of brands. “Brands, it seems, alongside ownership of copyright and trademarks, computer software and specialist know-how, are now at the heart of the intangible value investors place on companies.” As such, companies in the 21st century may find it necessary to relook their brand in terms of its relevancy to consumers and the changing marketplace. Successful rebranding projects can yield a brand better off than before.
Due to the tremendous impact that renaming and rebranding a company can have, it is critical to take the client through the process with great sensitivity and care. The new company identity and brand should be launched in a subtle and methodical manner in order to avoid alienating old customers, while aiming to attract new business prospects. There is no magic formula. However, there is a methodical process that involves careful strategy, memorable visuals and personal interactions, all of which must speak in unison for a customer to place full trust and invest their emotions in what is on offer. Marketing develops the awareness and associations in consumer memory so that customers know which brands best serve their needs. Once in a lead position, it is marketing, consistent product or service quality, sensible pricing and effective distribution that will keep the brand ahead of the pack and provide value to its owners. Corporations rebrand in order to respond to external and/or internal issues.
Firms have rebranding cycles in order to stay current with the times or set themselves ahead of the competition. Companies utilize rebranding as an effective marketing tool to hide malpractices of the past, thereby shedding negative connotations that could affect profitability. Corporations such as Citigroup, AOL, American Express, Goldman Sachs all utilize third-party vendors that specialize in brand strategy and the development of corporate identity. Companies invest valuable resources into rebranding and third-party vendors because it is a way to protect them from being blackballed by customers in a competitive market. Dr. Roger Sinclair, a leading expert on brand valuation and brand equity practice worldwide stated, “A brand is a resource acquired by an enterprise that generates future economic benefits.” Once a brand has negative connotations associated with it, it can only lead to decreased profitability and complete corporate failure. Companies differentiate themselves from competitors by incorporating practices from changing their logo to going green.
Differentiation from competitors is important in order to attract more customers and an effective way to draw in more desirable employees. The need to differentiate is prevalent in saturated markets such as the financial services industry. Organisations may rebrand intentionally to shed negative images of the past. Research suggests that "concern over external perceptions of the organisation and its activities" can function as a major driver in rebranding exercises. In a corporate context, managers can utilize rebranding as an effective marketing strategy to hide malpractices and avoid or shed negative connotations and decreased profitability. Corporations such as Philip Morris USA, Blackwater and AIG rebranded in order to shed negative images. Philip Morris USA rebranded its name and logo to Altria on January 27, 2003 due to the negative connotations associated with tobacco products that could have had potential to affect the profitability of other Philip Morris brands such as Kraft Foods. In 2008, AIG's image became damaged due to its need for a Federal bailout during the financial crisis.
AIG was bailed out because the United States Treasury stated that AIG was too big to fail due to its size and complex relationships with financial counterparties. AIG itself is a huge international firm; as a result, AIG Financial Advisors and AIG
Vikram Samvat. It uses solar sidereal years; the Vikram Samvat is notable because many medieval era inscriptions use it. It is said to be named after the legendary king Vikramaditya, but the term "Vikrama Samvat" does not appear in the historical records before the 9th century, rather the same calendaring system is found by other names such as Krita and Malava. In the colonial era scholarship, the era was believed to be based on the commemoration of King Vikramaditya expelling the Sakas from Ujjain; however epigraphical evidence and scholarship suggest that this theory has no historical basis and likely was an error. Starting in the 9th century and thereafter, epigraphical artwork uses Vikrama-Samvat, suggesting that sometime around the 9th-century, the Hindu calendar era, in use became popular as Vikram Samvat, while Buddhist and Jain epigraphy continued to use an era based on the Buddha or the Mahavira. According to popular tradition, the legendary king Vikramaditya of Ujjain established the Vikrama Samvat era after defeating the Śakas.
Kalakacharya Kathanaka by the Jain sage Mahesarasuri gives the following account: Gandharvasena, the then-powerful king of Ujjain, abducted a nun called Sarasvati, the sister of the monk. The enraged monk sought the help of the Śaka ruler King Sahi in Sistan. Despite heavy odds but aided by miracles, the Śaka king defeated Gandharvasena and made him a captive. Sarasvati was repatriated; the defeated king retired to the forest. His son, being brought up in the forest, had to rule from Pratishthana. On, Vikramaditya invaded Ujjain and drove away from the Śakas. To commemorate this event, he started a new era called the "Vikrama era"; the Ujjain calendar started around 58–56 BCE, the subsequent Shaka era calendar was started in 78 CE at Pratishthana. The association of the era beginning in 57 BCE with Vikramaditya is not found in any source before the 9th century CE; the earlier sources call this era by various names, including Kṛṭa, the era of the Malava tribe, or Samvat. The earliest known inscription that calls the era "Vikrama" is from 842 CE.
This inscription of Chauhana ruler Chandamahasena was found at Dholpur, is dated Vikrama Samvat 898, Vaishakha Shukla 2, Chanda. The earliest known inscription that associates this era with a king called Vikramaditya is dated 971 CE; the earliest literary work that connects the era to Vikramaditya is Subhashita-Ratna-Sandoha by the Jain author Amitagati. For this reason, multiple authors believe that the Vikram Samvat was not started by Vikramaditya, who might be a purely legendary king or the title adopted by a king who renamed the era after himself. V. A. Smith and D. R. Bhandarkar believed that Chandragupta II adopted the title Vikramaditya, changed the name of the era to "Vikrama Samvat". According to Rudolf Hoernlé, the king responsible for this change was Yashodharman: Hoernlé believed that he conquered Kashmir, is the same person as the "Harsha Vikramaditya" mentioned in Kalhana's Rajatarangini. Earlier, some scholars believed that the Vikrama Samavat corresponded to the Azes era of the Indo-Scythian king King Azes.
However, this was disputed by Robert Bracey following the discovery of an inscription of Vijayamitra, dated in two eras. The theory seems to be now discredited by Falk and Bennett, who place the inception of the Azes era in 47–46 BCE; the traditional New Year of Vikram Samvat is one of the many festivals of Nepal, marked by parties, family gatherings, the exchange of good wishes, participation in rituals to ensure good fortune in the coming year. It occurs in mid-April each year, coincides with the traditional new year in Assam, Burma, Kerala, Manipur, Punjab, Sri Lanka, Tamil Nadu and Thailand. In addition to Nepal, the Vikram Samvat calendar is recognized in North and East India, in Gujarat among Hindus. Hindu religious festivals are based on a Luni-Solar calendar, not Solar calendar, based on Vikram Samvat. In North India, the new year in Vikram Samvat starts from the first day of Chaitra Skukla paksha. In Buddhist communities, the month of Baishakh is associated with Buddha's Birthday, it commemorates the birth and passing of Gautama Buddha on the first full moon day in May, except in a leap year when the festival is held in June.
Although this festival is not held on the same day as Pahela Baishakh, the holidays fall in the same month of the Bengali and Theravada Buddhist calendars, are related through the spread of Hinduism and Buddhism in the Indian subcontinent. In Gujarat, the day after Diwali is celebrated as the first day of the Vikram Samvat calendar, the first day of the month Kartik; the Vikrami era is an ancient calendar and has been used by Hindus and Sikhs. It is one of the several regional Hindu calendars that have been in use on the Indian subcontinent, it is based on twelve synodical lunar months and 365 solar days; the lunar new year starts on the new moon in the month of Chaitra. This day, known as Chaitra Sukhladi, is a restricted holiday in India; the Vikrami Samvat has been in use in the Indian subcontinent since ancient times, remains in use by the Hindus in north, w
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 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