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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] |
SD40
SD40 may refer to: * Canon PowerShot SD40, a digital camera * EMD SD40, a diesel-electric locomotive * South Dakota Highway 40 * SD-40 alcohol, ethanol denatured alcohol, denatured by adding denatonium benzoate * School District 40 New Westminster, a British Columbian school district for the city of New Westminster {{Letter-NumberCombDisambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encyclopedia Britannica
An encyclopedia is a reference work or compendium providing summaries of knowledge, either general or special, in a particular field or discipline. Encyclopedias are divided into article (publishing), articles or entries that are arranged Alphabetical order, alphabetically by article name or by thematic categories, or else are hyperlinked and searchable. Encyclopedia entries are longer and more detailed than those in most dictionary, dictionaries. Generally speaking, encyclopedia articles focus on ''factual information'' concerning the subject named in the article's title; this is unlike dictionary entries, which focus on Linguistics, linguistic information about words, such as their etymology, meaning, pronunciation, use, and grammar, grammatical forms.Béjoint, Henri (2000)''Modern Lexicography'', pp. 30–31. Oxford University Press. Encyclopedias have existed for around 2,000 years and have evolved considerably during that time as regards language (written in a major inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Religion In Ancient Rome
Religion in ancient Rome consisted of varying imperial and provincial religious practices, which were followed both by the Roman people, people of Rome as well as those who were brought under its rule. The Romans thought of themselves as highly religious, and attributed their success as a world power to their collective piety () in maintaining Pax deorum, good relations with the gods. Their Polytheism, polytheistic religion is known for having honoured List of Roman deities, many deities. The presence of Magna Graecia, Greeks on the Italian peninsula from the beginning of the historical period influenced Culture of ancient Rome, Roman culture, introducing some religious practices that became fundamental, such as the of Apollo. The Romans looked for common ground between their major gods and those of the Greeks (), adapting Greek mythology, Greek myths and iconography for Latin literature and Roman art, as the Etruscans had. Etruscan religion was also a major influence, partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numa Pompilius
Numa Pompilius (; 753–672 BC; reigned 715–672 BC) was the Roman mythology, legendary second king of Rome, succeeding Romulus after a one-year interregnum. He was of Sabine origin, and many of Rome's most important religious and political institutions are attributed to him, such as the Roman calendar, Vestal Virgins, the cult of Mars, the cult of Jupiter, the cult of Romulus, and the office of ''pontifex maximus''. Genealogy According to Plutarch, Numa was the youngest of Pomponius's four sons, born on the day of Rome's founding (traditionally, 21 April 753 BC). He lived a severe life of discipline and banished all luxury from his home. Titus Tatius, king of the Sabines and a colleague of Romulus, gave in marriage his only daughter, Tatia (wife of Numa Pompilius), Tatia, to Numa. After 13 years of marriage, Tatia died, precipitating Numa's retirement to the countryside. According to Livy, Numa resided at Cures, Sabinum, Cures immediately before being elected king.Livy, ''Ab u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
March Equinox
The March equinox or northward equinox is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox is known as the vernal equinox (or spring equinox) in the Northern Hemisphere and as the autumnal equinox (or fall equinox) in the Southern Hemisphere. On the Gregorian calendar at 0° longitude, the northward equinox can occur as early as 19 March (which happened most recently in 1796, and will happen next in 2044), and it can occur as late as 21 March (which happened most recently in 2007, and will happen next in 2102). For a common year the computed time slippage is about 5 hours 49 minutes ''later'' than the previous year, and for a leap year about 18 hours 11 minutes ''earlier'' than the previous year. Balancing the increases of the common years against the losses of the leap years keeps the calendar date of the March equinox from drifting more than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Tropical Year
A mean is a quantity representing the "center" of a collection of numbers and is intermediate to the extreme values of the set of numbers. There are several kinds of means (or "measures of central tendency") in mathematics, especially in statistics. Each attempts to summarize or typify a given group of data, illustrating the magnitude and sign of the data set. Which of these measures is most illuminating depends on what is being measured, and on context and purpose. The '' arithmetic mean'', also known as "arithmetic average", is the sum of the values divided by the number of values. The arithmetic mean of a set of numbers ''x''1, ''x''2, ..., x''n'' is typically denoted using an overhead bar, \bar. If the numbers are from observing a sample of a larger group, the arithmetic mean is termed the '' sample mean'' (\bar) to distinguish it from the group mean (or expected value) of the underlying distribution, denoted \mu or \mu_x. Outside probability and statistics, a wide ran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Calendar
A solar calendar is a calendar whose dates indicates the season or almost equivalently the apparent position of the Sun relative to the stars. The Gregorian calendar, widely accepted as a standard in the world, is an example of a solar calendar. The main other types of calendar are lunar calendar and lunisolar calendar, whose months correspond to cycles of Moon phases. The months of the Gregorian calendar do not correspond to cycles of the Moon phase. The Egyptians appear to have been the first to develop a solar calendar, using as a fixed point the annual sunrise reappearance of the Dog Star— Sirius, or Sothis—in the eastern sky, which coincided with the annual flooding of the Nile River. They constructed a calendar of 365 days, consisting of 12 months of 30 days each, with 5 days added at the year’s end. The Egyptians’ failure to account for the extra fraction of a day, however, caused their calendar to drift gradually into error. Examples The oldest solar calendar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Calendar
The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. Although the term is primarily used for Rome's pre-Julian calendars, it is often used inclusively of the Julian calendar established by Julius Caesar in 46 BC. According to most Roman accounts, #Romulus, their original calendar was established by their Roman legend, legendary list of kings of Rome, first king Romulus. It consisted of ten months, beginning in spring with March and leaving winter as an unassigned span of days before the next year. These months each had 30 or 31 days and ran for 38 nundinal cycles, each forming a kind of eight-day weeknine days inclusive counting, counted inclusively in the Roman mannerand ending with religious rituals and a Roman commerce, public market. This fixed calendar bore traces of its origin as an observational calendar, observational lunar calendar, lunar one. In particular, the most important days of each monthits kalends, nones (calendar), nones, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julius Caesar
Gaius Julius Caesar (12 or 13 July 100 BC – 15 March 44 BC) was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in Caesar's civil war, a civil war. He subsequently became Roman dictator, dictator from 49 BC until Assassination of Julius Caesar, his assassination in 44 BC. Caesar played a critical role in Crisis of the Roman Republic, the events that led to the demise of the Roman Republic and the rise of the Roman Empire. In 60 BC, Caesar, Marcus Licinius Crassus, Crassus, and Pompey formed the First Triumvirate, an informal political alliance that dominated Roman politics for several years. Their attempts to amass political power were opposed by many in the Roman Senate, Senate, among them Cato the Younger with the private support of Cicero. Caesar rose to become one of the most powerful politicians in the Roman Republic through a string of military victories in the G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leap Year Bug
The leap year problem (also known as the leap year bug or the leap day bug) is a problem for both digital (computer-related) and non-digital documentation and data storage situations which results from errors in the calculation of which years are leap years, or from manipulating dates without regard to the difference between leap years and common years. Categories Leap year bugs typically fall into two categories, based on the amount of impact they may have in real-world usage: # Those that lead to error conditions, such as exceptions, error return codes, uninitialized variables, or endless loops # Those that lead to incorrect data, such as off-by-one problems in range queries or aggregation Examples Python The following Python code is an example of a Category 1 leap year bug. It will work properly until today becomes February 29. Then, it will attempt to create a February 29 of a common year, which does not exist. The date constructor will raise a ValueError with the message ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Period
In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the object takes to complete a full rotation around its axis relative to the background stars ( inertial space). The other type of commonly used "rotation period" is the object's '' synodic rotation period'' (or ''solar day''), which may differ, by a fraction of a rotation or more than one rotation, to accommodate the portion of the object's orbital period around a star or another body during one day. Measuring rotation For solid objects, such as rocky planets and asteroids, the rotation period is a single value. For gaseous or fluid bodies, such as stars and giant planets, the period of rotation varies from the object's equator to its pole due to a phenomenon called differential rotation. Typically, the stated rotation period for a giant pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
