Century Leap Year
A century leap year is a leap year in the Gregorian calendar that is evenly divisible by 400. Like all leap years, it has an extra day in February for a total of 366 days instead of 365. In the obsolete Julian calendar, all years that were divisible by 4, including end-of-century years, were considered leap years. The Julian rule, however, adds too many leap days (about three extra leap days in 400 years), which resulted in the calendar drifting gradually with respect to the astronomical seasons. To remedy this, Pope Gregory XIII introduced in 1582 a slightly modified version of the Julian calendar, the Gregorian calendar, where century years are leap years only if they are divisible by 400. This eliminates three of the four end-of-century years in a 400-year period. For example, the years 1600, 2000, 2400, and 2800 are century leap years since those numbers are evenly divisible by 400, while 1700, 1800, 1900, 2100, 2200, 2300, 2500, 2600, 2700, 2900, and 3000 are common year ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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S 5 3 Kalendernotizen S 102 103 1600 Feb
S, or s, is the nineteenth letter of the Latin alphabet, used in the English alphabet, the alphabets of other western European languages and other latin alphabets worldwide. Its name in English is ''ess'' (pronounced ), plural ''esses''. History Northwest Semitic šîn represented a voiceless postalveolar fricative (as in 'ip'). It originated most likely as a pictogram of a tooth () and represented the phoneme via the acrophonic principle. Ancient Greek did not have a "sh" phoneme, so the derived Greek letter Sigma () came to represent the voiceless alveolar sibilant . While the letter shape Σ continues Phoenician ''šîn'', its name ''sigma'' is taken from the letter ''Samekh'', while the shape and position of ''samekh'' but name of ''šîn'' is continued in the '' xi''. Within Greek, the name of ''sigma'' was influenced by its association with the Greek word (earlier ), "to hiss". The original name of the letter "Sigma" may have been ''san'', but due to the earl ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Leap Year
A leap year (also known as an intercalary year or bissextile year) is a calendar year that contains an additional day (or, in the case of a lunisolar calendar, a month) compared to a common year. The 366th day (or 13th month) is added to keep the calendar year synchronised with the astronomical year or seasonal year. Since astronomical events and seasons do not repeat in a Natural number, whole number of days, calendars having a constant number of days each year will unavoidably drift over time with respect to the event that the year is supposed to track, such as seasons. By inserting ("Intercalation (timekeeping), intercalating") an additional day—a leap day—or month—a leap month—into some years, the drift between a civilization's dating system and the physical properties of the Solar System can be corrected. An astronomical year lasts slightly less than 365 days. The historic Julian calendar has three common years of 365 days followed by a leap year of 366&nb ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gregorian Calendar
The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull issued by Pope Gregory XIII, which introduced it as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years slightly differently to make the average calendar year 365.2425 days long rather than the Julian calendar's 365.25 days, thus more closely approximating the 365.2422-day tropical year, "tropical" or "solar" year that is determined by the Earth's revolution around the Sun. The rule for leap years is that every year divisible by four is a leap year, except for years that are divisible by 100, except in turn for years also divisible by 400. For example 1800 and 1900 were not leap years, but 2000 was. There were two reasons to establish the Gregorian calendar. First, the Julian calendar was based on the estimate that the average solar year is exactly 365.25 days long, an overestimate of a li ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Divisible
In mathematics, a divisor of an integer n, also called a factor of n, is an integer m that may be multiplied by some integer to produce n. In this case, one also says that n is a '' multiple'' of m. An integer n is divisible or evenly divisible by another integer m if m is a divisor of n; this implies dividing n by m leaves no remainder. Definition An integer n is divisible by a nonzero integer m if there exists an integer k such that n=km. This is written as : m\mid n. This may be read as that m divides n, m is a divisor of n, m is a factor of n, or n is a multiple of m. If m does not divide n, then the notation is m\not\mid n. There are two conventions, distinguished by whether m is permitted to be zero: * With the convention without an additional constraint on m, m \mid 0 for every integer m. * With the convention that m be nonzero, m \mid 0 for every nonzero integer m. General Divisors can be negative as well as positive, although often the term is restricted to posi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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United States Naval Observatory
The United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depot of Charts and Instruments, it is one of the oldest scientific agencies in the United States, and remains the country's leading facility for astronomical and timing data. The observatory is located in Northwest Washington, D.C. at the northwestern end of Embassy Row. It is among the few pre-20th century astronomical observatories located in an urban area. In 1893, in an effort to escape light pollution, it was relocated from Foggy Bottom near the city's center, to its Northwest Washington, D.C. location. The USNO has conducted significant scientific studies throughout its history, including measuring the speed of light, observing solar eclipses, and discovering the moons of Mars. Its achievements include providing data for the first ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Julian Calendar
The Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year (without exception). The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church and in parts of Oriental Orthodox Churches, Oriental Orthodoxy as well as by the Amazigh, Amazigh people (also known as the Berbers). The Julian calendar was proposed in 46 BC by (and takes its name from) Julius Caesar, as a reform of the earlier Roman calendar, which was largely a lunisolar calendar, lunisolar one. It took effect on , by his edict. Caesar's calendar became the predominant calendar in the Roman Empire and subsequently most of the Western world for more than 1,600 years, until 1582 when Pope Gregory XIII promulgated a revised calendar. Ancient Romans typically designated years by the names of ruling consuls; the ''Anno Domini'' system of numbering years was not devised until 525, and became widespread in Europe in the eighth cent ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Pope Gregory XIII
Pope Gregory XIII (, , born Ugo Boncompagni; 7 January 1502 – 10 April 1585) was head of the Catholic Church and ruler of the Papal States from 13 May 1572 to his death in April 1585. He is best known for commissioning and being the namesake for the Gregorian calendar, which remains the internationally accepted civil calendar to this day. Early biography Youth Ugo Boncompagni was born the son of Cristoforo Boncompagni (10 July 1470 – 1546) and Angela Marescalchi, and paternal grandson of Giacomo Boncompagni and Camilla Piattesi, in Bologna, where he studied law and graduated in 1530. He later taught jurisprudence for some years, and his students included notable figures such as Cardinals Alexander Farnese, Reginald Pole and Charles Borromeo. He had an illegitimate son after an affair with Maddalena Fulchini, Giacomo Boncompagni, but before he took holy orders, making him the last Pope to have left issue. Career before papacy At the age of 36 he was summoned to Rome ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Common Year
A common year is a calendar year with 365 days, as distinguished from a ''leap year'', which has 366 days. More generally, a common year is one without Intercalation (timekeeping), intercalation. The Gregorian calendar, used by the majority of the world, employs both common years and leap years. This is to keep the calendar aligned with the tropical year, which does not contain an exact number of days. A common year is approximately a quarter day (six hours) shorter than a tropical year, which has 365.24 days. If the Gregorian calendar only used common years and omitted leap years, the calendar would be out of sync with the tropical year by approximately 24 days in 100 years. In the Gregorian calendar, 303 out of every 400 years are common years. Leap years are any years that are divisible by 4, unless it can also be divided by 100, in which case it is a common year. One exception is if the year can be divided by 4, 100, ''and'' 400 - these years are leap years. The extra common ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Adoption Of The Gregorian Calendar
The adoption of the Gregorian Calendar has taken place in the history of most cultures and societies around the world, marking a change from one of various traditional (or "old style") dating systems to the contemporary (or "new style") system the Gregorian calendar which is widely used around the world today. Some states adopted the new calendar in 1582, others not before the early twentieth century, and others at various dates between. A few have yet to do so, but except for these, the Gregorian calendar is now the world's universal civil calendar, old style calendars remaining in use in religious or traditional contexts. During and for some time after the transition between systems, it has been common to use the terms "Old Style" and "New Style" when giving dates, to indicate which calendar was used to reckon them. The Gregorian calendar was decreed in 1582 by the papal bull by Pope Gregory XIII, to correct an error in the Julian calendar that was causing an erroneous ca ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Old Style And New Style Dates
Old Style (O.S.) and New Style (N.S.) indicate dating systems before and after a calendar change, respectively. Usually, they refer to the change from the Julian calendar to the Gregorian calendar as enacted in various Europe, European countries between 1582 and 1923. In England, Wales, Ireland and British America, Britain's American colonies, there were two calendar changes, both in 1752. The first adjusted the start of a new year from 25 March (Lady Day, the Feast of the Annunciation) to 1 January, a change which Scotland had made in 1600. The second discarded the Julian calendar in favour of the Gregorian calendar, skipping 11 days in the month of September to do so.. "Before 1752, parish registers, in addition to a new year heading after 24th March showing, for example '1733', had another heading at the end of the following December indicating '1733/4'. This showed where the Historical Year 1734 started even though the Civil Year 1733 continued until 24th March. ... We as h ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Units Of Time
A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The SI base unit, base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom. The exact modern SI definition is "[The second] is defined by taking the fixed numerical value of the cesium frequency, , the unperturbed ground-state hyperfine transition frequency of the cesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1." Historically, many units of time were defined by the movements of astronomical objects. * Sun-based: the year is based on the Earth's orbit, Earth's orbital period around the sun. Historical year-based units include the Olympiad (four years), the lustrum (five years), the indiction (15 years), the decade, the century, and the millennium. * Moon-based: the month is based on the Orbit of the Moon, Moon's orbital per ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Calendars
A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A calendar date, date is the designation of a single and specific day within such a system. A calendar is also a physical record (often paper) of such a system. A calendar can also mean a list of planned events, such as a court calendar, or a partly or fully chronological list of documents, such as a calendar of wills. Periods in a calendar (such as years and months) are usually, though not necessarily, synchronized with the cycle of the solar calendar, sun or the lunar calendar, moon. The most common type of pre-modern calendar was the lunisolar calendar, a lunar calendar that occasionally adds one intercalary month to remain synchronized with the solar year over the long term. Etymology The term ''calendar'' is taken from , the term for the first day of the month in the Roman calendar, related to the verb 'to call out', referring to the " ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |