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Chinese New Year or the Spring Festival (see also Names) is a festival that celebrates the beginning of a new year on the traditional lunisolar Chinese calendar.Marking the end of winter and the beginning of spring, observances traditionally take place from Chinese New Year's Eve, the evening preceding the first day of the year, to the Lantern Festival, held on the 15th day of the year.
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The number π (/paɪ/; spelled out as "pi") is a mathematical constant that is the ratio of a circle's circumference to its diameter, approximately equal to 3.14159. The number π appears in many formulae across mathematics and physics. It is an irrational number, meaning that it cannot be expressed exactly as a ratio of two integers, although ...
Viète. de Moivre. Euler. Fourier. v. t. e. In trigonometry, trigonometric identities are equalities that involve trigonometric functions and are true for every value of the occurring variables for which both sides of the equality are defined. Geometrically, these are identities involving certain functions of one or more angles.
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The official abbreviation for Coordinated Universal Time is UTC. This abbreviation comes as a result of the International Telecommunication Union and the International Astronomical Union wanting to use the same abbreviation in all languages. The compromise that emerged was UTC,which conforms to the pattern for the abbreviations of the variants of U...
Time zones around the world are expressed using positive or negative offsets from UTC, as in the list of time zones by UTC offset. The westernmost time zone uses UTC−12, being twelve hours behind UTC; the easternmost time zone uses UTC+14, being fourteen hours ahead of UTC. In 1995, the island nation of Kiribati moved those of its atolls in the Lin...
UTC divides time into days, hours, minutes, and seconds. Days are conventionally identified using the Gregorian calendar, but Julian day numbers can also be used. Each day contains 24 hours and each hour contains 60 minutes. The number of seconds in a minute is usually 60, but with an occasional leap second, it may be 61 or 59 instead. Thus, in the...
In 1928, the term Universal Time (UT) was introduced by the International Astronomical Union to refer to GMT, with the day starting at midnight. Until the 1950s, broadcast time signalswere based on UT, and hence on the rotation of the Earth. In 1955, the caesium atomic clock was invented. This provided a form of timekeeping that was both more stabl...
Earth's rotational speed is very slowly decreasing because of tidal deceleration; this increases the length of the mean solar day. The length of the SI second was calibrated on the basis of the second of ephemeris time and can now be seen to have a relationship with the mean solar day observed between 1750 and 1892, analysed by Simon Newcomb. As a ...
As the Earth's rotation continues to slow, positive leap seconds will be required more frequently. The long-term rate of change of LOD is approximately +1.7 ms per century. At the end of the 21st century, LOD will be roughly 86,400.004 s, requiring leap seconds every 250 days. Over several centuries, the frequency of leap seconds will become proble...
CurrentUTC timeW3C Specification about UTC Date and Time and RFC 3339, based on ISO 8601Wireless network technologies. In telecommunications, 5G is the fifth-generation technology standard for cellular networks, which cellular phone companies began deploying worldwide in 2019, and is the successor to 4G technology that provides connectivity to most current mobile phones. Like its predecessors, 5G networks are cellular networks, in ...
A conglomerate (/kəŋˈɡlɒmərət/) is a type of multi-industry company that consists of several different and unrelated business entities that operate in various industries under one corporate group.[1] A conglomerate usually has a parent company that owns and controls many subsidiaries, which are legally independent but financially and ...
