67. Stüssy deporte x 67. Nike Air Huarache Light 19993 Las 100 mejores zapatillas de deporte de la 36f11f4




World Clock

WorldClock.com provides accurate world time, statistics and weather in major cities across the world.

With incomparable time-telling precision, World Clock is the perfect point of reference for travelers and business people alike. Whether you’re looking to book a flight, schedule an international teleconference, use our time zone converter or our time zone map and observe the trading hours of an overseas business, WorldClock.com can show you the time in a matter of seconds.

There are two standards by which a country’s time zone is categorized; the older of the two standards is Greenwich Mean Time (GMT) and the more modern of the two standards is Coordinated Universal Time (UTC). However, there is no actual time difference between GMT and UTC and therefore the two can be used interchangeably.

Time zones are regions of the earth divided by lines of longitude. There are 24 different time zones on earth to correlate with the 24 hours in each day and which are displayed in our time zone map here at World Clock. The UK sets the standard for Greenwich Mean Time at “GMT 0” and other countries can calculate their time zone in accordance with how many hours they are ahead of or behind the UK. For instance, Saudi Arabia, which is 3 hours ahead of the UK, has a time zone of “GMT +3” and Colombia, which is 5 hours behind the UK, has a time zone of “GMT -5”.

Daylight Savings Time (DST) is practiced in certain parts of the world in order to allow for more hours of daylight during the working day. Therefore, for half of the year some countries adjust their clocks by one hour. World Clocks are adjusted forward by one hour in the early spring and then set back by one hour in the autumn. This means that, in the spring, a clock will go from 4:00 Standard Time to 5:00 DST.

Ian Shutts

Your Current Local Time And Location
Querying time server...
67. Stüssy deporte x 67. Nike Air Huarache Light 19993 Las 100 mejores zapatillas de deporte de la 36f11f4
--:------
-- ---- ----
67. Stüssy deporte x 67. Nike Air Huarache Light 19993 Las 100 mejores zapatillas de deporte de la 36f11f4
Search Country / City to Check The Local Time
Local Time In Major Cities City Time Now Time Difference City Time Now Time Difference
Time in Amsterdam
Time in Bangkok
Time in Beijing
Zapatillas Nike Free Flyknit Mujeres Nike Free V2 Hombre .2013 Nike Free Men: Nike, zapatillas de tenis, zapatos, Converse, Mizuno .Zapatillas para correr Nike Free Run 3 Womens Light Green, zapatillas deportivas nike .Zapatillas Nike Free Run 3 para mujer negras [nike04 1106] .nike free run cheap, zapatos de mujer Nike Air Max 95 azul cielo .nike huarache run ultra se, Nike Free Run 3 para mujer verde claro 2013 .nike free rn flyknit para la venta, Mujeres Nike Free Run Grey Purple .Consigue las zapatillas de running Nike Air Max Zero QS 2015 para hombre / mujer negras .Nike Nike Nike Nike Nike Nike Nike Nike Nike 3 .Zapatillas Mujer Nike Air Max Verde | .Cheap Nike Free Run Zapatos Mujeres | .Nike Free Trainer Youtube V4 Womens Wrinkle Free .Tiendas de zapatos en línea Nike Free Run 2 Womens Online Sulbvy 1VqO2ZEX @ v .Compre Nike Nike Running Nike Free Men en línea Vea nuestro nuevo .Nike Nike Nike running gratis + 3 mujeres Chicago Outlet, Nike Nike Nike .Zapatillas nike para niños pequeños, Zapatillas para correr Nike Free Run 2 para hombre .Ahorre 60% en precios ya reducidos Nike Nike Nike gratis ejecute 2 mujeres .Nike Zoom Elite 8 crítica | .Nike MUJERES NIKE GRATIS Free Run Chicago Outlet Precio más bajo garantizado .Comprar Nike Nike Nike Free Run 3 Men Original Ofertas exclusivas Barato .2014 mens nike air max, para hombre Nike Free Run gris rojo blanco, para mujer .2017 Comprar barato Nike Air Max 1 Zapatos de mujer Oferta Black Friday .Descuento en la Web Nike Air Max 2017 Cuero Verde Azul Blanco Entrenamiento .Nike Kids Running Shoes Nueva llegada Nike Downshifter 8: Cheap .nike air max thea flyknit, calidad 100% para mujer nike v4 .nike free tr fit niños zapatos rosa azul [nike 16401 0557] .27 mejores imágenes gratuitas de nike run 3 en Pinterest | .2017 Comprar baratos Nike Air Max 97 Zapatos Mujer Oferta Black Friday .nike liquidación de liquidación barata, Tienda de descuento Nike Air Max 90 High .472489 700 90 Zapatos Negro Blanco, nike air max en oferta, zapatos nike para .Venta al por mayor Nike Air Max 2018 élite AIR WAPOR MAX Sports shoes 1: 1 .Nike Air Max Old School Blue Black | .Nike Air Max Plus TN Ultra Hombre Nike Sportswear Zapatos baratos Blanco .dónde comprar zapatillas de deporte Nike White / Photo Blue Pale Gray White (Hombre) .Moda Nike Air Max 90 Mens Azul Nueva Loyal326 Cheap Sale UK All .Descuento Nike Air Max Tavas Mens Online Mugua042 Cheap Sale UK All .nike huarache ultra rojo, puntos fluorescentes rosas negras mujeres baratas uk .Cheap Nike Air Presto Mens Online Loyal1840 Cheap Sale UK All .nike clearance orlando, Nike Air Max TN Black Blue para hombre, nike 24 7 .Cheap Unisex Nike Air Max Zero Womens Shoes en línea del Reino Unido Venta .Nike Nike Nike Air Max Zero para mujer | .Zapatillas Nike Air VaporMax Flyknit RUNNING (849558 021) .Cómodo Nike Air Max 97 2018 Royal Blue Blanco Casual para hombre .Envío gratis Nike Air Max 97 UL 17 SE Triple Black 824452 001 Hombres .Zapatos originales Nike Air Max 2013 para comprar barato | Nike Air auténtica .Descuento Nike Air Max 90 Hombres Zapatillas Blanco Azul Rojo JQ362874 .Zapatillas Nike Air Max 90 Premium para mujer Fireberry / Pink Pow .Nike Air Max 90 | .Nike Air Max 270 Black / Neon Green en venta | .nike free rn flyknit 2, Nike Free Flyknit zapatillas para hombre .Air Max BW Nike Running Zapatillas Zapatos Mujeres Negro Rosa Blanco, nike .Nike Wmns Air Max 97 Ultra Black Confetti AO2325 002 sneakAvenue .Nike Air Max 95 Ultra Se Pull Tab Pink Entrenadores Oferta .Nike Air Max 1 Tienda Online UK Shoes Misty Grey Snowy White Black .Zapatillas Nike Nike Air Max 1 Wide, Nike Nike Nike Air Max 1 .Nike Zoom KD VI Nike Zoom KD VI a la venta .Por qué los atletas aman el Nike Epic React Flyknit | .Run Shoes 2013 Nike Free Women Outlet EE. UU., 100% de calidad .Dennishayes: Mejor tienda oficial de fábrica de Nike Air Presto para hombre .Nike Airmax 90 Youth Negro Amarillo Nike Air Max Excellerate 4 Azul .Nike Men Nike Nike Air más uptempo Descuento, Nike Men Nike Nike air .Zapatillas nike roshe two cheap, Nuevas zapatillas Nike Lunar 3 Flyknit Mujer Oferta .nike liquidación tienda california, Nike Air Max Men Air Max, nike .Descuento Nike Nike Air Max 97 al por mayor .Zapatos Nike Roshe Run Pattern baratos para usted: zapatos Nike baratos en línea .nike cheap running clearance, Zapatos baratos de Nike Roshe para hombre .Nike Roshe One Zapatos casuales Mujeres Negro | .Zapatos NikeLab Air Max 97 Plus para hombre (Negro) O90IHRQR Nike Men .40 $ al por mayor nike jordan retro 13 xiii niños electricidad bordar .nike air max zero cheap, air foamposite uno ido de pesca, nike .Auténtico Nike Air Max 2017 negro rojo blanco en línea SG5t4ZN, precio .De calidad superior Nike Flyknit Air Max Sale, compre barato Nike Flyknit Air .Nike Nike SB Outlet para hombre, Nike Nike SB Mens Online Here Outlet .Zapatillas para correr Nike Air Max 90 PRM EM para hombre / para mujer Blanco .Descuento Nike Air Jordan Future Outlet, compre Nike Air Jordan Future .Nike Nike Nike Air Jordan 10 Outlet para hombre a la venta, rápido y gratis .Nike Performance FREE TR FIT 5 Calzado deportivo negro / lava caliente .nike zapatos de fútbol más baratos, nike air max 87 mujeres blanco rojo azul .Nike Zapatillas de baloncesto Nike Zoom Lebron Soldier Envío gratis Nike .calcetines con bandera de nike usa, zapatillas Nike Kwazi con zapatos de hombre, nike running .Zapatillas de baloncesto Nike Soldier 11 Black y Gold LeBron James PE nuevas .348 mejores imágenes de chica Jordan en Pinterest | .23 mejores imágenes de zapatos en Pinterest | .nike air max plus black, Descuento Air Jordan 1 New Style Gray White .Nike 854272 003 Air Jordan XXXI N7 zapatos de baloncesto para hombre en negro .Fechas de lanzamiento de Nike Sneakers 2017 2018 .OFF WHITE x Nike Air Jordan 1 AJ1 Blanco cheque de fiar más barato PK God .Nike Air Air Jordan Womens 14 Wide Range, Nike Air Air Jordan Womens .Nike Air Max 90 para hombre: Zapatos Nike baratos, descuento del 50% en Nike .Garantía 100% de alta calidad, nuevos zapatos de Nike Air Air Jordan 4 Venta .Nike MEN NIKE AIR Air Jordan 6 Chicago Outlet Precio bajo garantizado el .Nike Flyknit Air Max: Outlet Store Air Max Zapatillas de running Nike .Zapatillas Nike Air Huarache Ultra para hombre. .Nike Nike aire Air max flyknit mujeres mayorista Disfrute sin impuestos sobre las ventas .691 mejores imágenes de zapatos en Pinterest | .Zapatos en línea New York Nike nuevos Air Air Jordan Womens Spizike Sin impuestos .Marca Nike Air Max 90 Womens Black Outlet Joomlas Store [385941014] .Marca Nike Air Max 90 Womens Black Outlet Joomlas Store [385851005] .Nike Air Max 90 Sneakerboot azul blanco .2013 nike air max shoes, Top Nike Air Max 90 Mujeres Hyperfuse Pink .Comprar zapatos originales nike air max 90 para mujer rosa gris xq nike huarache .Nike air max 90 vt (womens) barato a la venta rebaja hasta 60% de descuento .Nike Air Jordan 1 Mid Red Black Mujeres | .100% calidad Nike Air Max 90 para mujer corriendo Q353 y llmWcR zapatos blanco .Zapatillas de mujer Nike Air Max 90 Rosa para mujer .nike huarache tacos rojo, Air Max 2016 Negro Amarillo, nike free run .Zapatillas de baloncesto Nike Ua Under Armour curry one Oferta en el Reino Unido, ahorra .Nike Brand Shoes Tienda en línea 2017 Aright Online Nike Shoes Men s .Zapatillas de running Nike Air Max Sequent para hombre, gris oscuro .Nike Mens Hurley Slugger Premium Black Heather, nike gratis, nike .Liquidación Nike Flyknit Free Shoes Hombre Naranja / Blanco En Oferta .Nike ancha de mujer | .23 mejores imágenes de zapatos en Pinterest | .Nike Free Run 2 Triple Black | .nike free rn motion flyknit, zapatos de mujer Nike Kyrie 1 Dream, nike air .15 mejores imágenes de Pisados ​​Transados ​​en Pinterest | .Nike Zoom Winflo 4 .Nike Air Max Triax 96 mataría por estas escuelas antiguas: (sacudió este .Nike Stock alcanza el récord histórico de todos los tiempos | .Nike está dejando caer un Colourway negro para el nuevo Epic React Flyknit .NIKE ZOOM FLYKNIT STREAK 6 (VOLT) / PAZ X9 YouTube .Zapatillas para correr Nike Air Zoom Streak LT 4 SP18 Guardar y comprar en línea .Nike Epic React Flyknit College Navy Racer azul AQ0067 400 .Revisión de calzado: Nike Epic React Flyknit Livemint .Mujeres Nike Free V2 Hot Sale Mujeres de buena calidad Nike Free .paseo descalzo para mujer nike gratis v3 .Classic Nike Free 5. 0 TR Fit 3 Black Red 579968 016 Hombre corriendo .Compre zapatillas Nike Womens Free V4 rosa / blanco / naranja .zapatos de agua nike .Nike Free Flyknit Hombres Negro Blanco [FYF5M10]: Nike Huarache .NIKE FLYKNIT RACER Official NIKE MIXED BARATO (TAMAÑO HOMBRE) NEGRO .Nike Magista Obra FG Nike Fútbol Nike Zapatos baratos 641322 010 Gery .La tienda de pinterest en | .nike free nike free run sneaker tela de malla de hombres de color mezclado .bolsa de baloncesto nike usa, precio bajo en Nike Women s Air Max Thea Prm .Jersey de hockey barato de nike usa, Nike Performance PRIME HYPE DF 2016 .nike free rn flyknit, zapatillas de running Nike Air Max Print para mujer .Zapatillas Hombre Nike Air Max 90 Blanco Negro Camo, outlet nike, nike .Zapatillas de running Nike Free RN Flyknit para hombre .Ventas al por menor Nike Dark Turquoise 2014 / Verde / Negro Gratis 2014 .Zapatillas informales para mujer Nike Air Zoom Mariah Flyknit Racer .X Girl Nike Free Leopard Comprar | .nike roshe cheap, zapatos de huarache para hombre nike air yd05100109, nike gratis .Serie Lunarlon para mujer: Nike Rendimiento confiable para hombre Kyrie II .Nike Free Men: Los hombres y mujeres más populares Nike Air Max Cb .Nike AIR MAX 95 PREMIUM Gris / Seta / Vela | .Nike Womens Lunarglide + 3 LX Liu Xiang Pack 2 Max Orange | .Gran variedad de zapatillas para mujer Nike Air Max Thea púrpura oscuro .Nike Nike Blazer High Liquidación de venta de mujeres en línea | .Nike Nike gratis v5 womens Discount Online Store, Compre ahora Can .Hombres Nike Free TR Fit 3 Breathe Grey Black Shoes | .Nike Men Roshe Two Flyknit (escuadrón universitario azul marino / blanco negro) .Venta al por mayor Nike zoom WINFLO 4 negro azul verde blanco 898466 003 Mens .Comprar hombres: Nike Road Running Shoes / Air Zoom Structure 20 Solstice .Nike Air Zoom Winflo 4 para hombre .Nike Nike Air Air Max 24 7 Hombres Envío gratis, Nike Nike Air Air Max .Zapatillas Nike Lunar Vapor Pro negras / Rush azul / blancas, hombre Nike .Nike Heel Air Sole ¿Qué es Nike Air Max | .Air Max 90 Mens Gris Blanco Negro Original Auténtico NIKE 530, venta .Sombrero de punto nike usa, Nike v2 gratis para hombre verde fluorescente .Zapatillas de running Nike Roshe One para hombre | .zapatos de hombre nike air presto negro amarillo [nike 16401 0482] .nike air max gris, Nike Free V4 Zapatos para mujer gris oscuro .Nike gratis v2 hombres blanco zapatillas deportivas naranja nike gratis .Nike Shoes Store Nike Sneakers, Nike Outlet Store .Zapatos gratuitos para hombre: la mejor calidad Zapatos Nike Free V2, Adidas .Zapatos de entrenamiento Nike Zapatos deportivos de hombre para zapatos JCPenney .Zapatillas Nike Running Jcpenney Naranja Nike Free Runs Black Cheap .Air Max 90 Moda Nike Running Zapatillas Zapatos Hombres Blanco Verde, nike .Zapatillas de running Nike Dual Fusion Run Msl para hombre Comprar blanco, metalizado .Gratis Rn Flyknit Tops Zapatos Hombre Negro Nike Envío gratis 543Dtvbndu .Wmns Nike Air Relentless 6 Msl Blackwhite Antracita Daftar actualización .Air Vapormax Hombres Nike Mag Hombres Zapatos Nike Air Mag Traffic Nike .Compre las mejores zapatillas Nike Free Run 2013 Black Green Flex Experience RN .Nike Mujer Air Max 97 Ultra UL 17 SE Burdeos Estaño Vino Púrpura .Hermoso rojo blanco Nike Free H3 | CE | e3 v4 Zapatos para correr de los hombres .Nike Air Max 97 | .Nike Air Max 97 Ultra Lux AH6805 001 para mujer | .Zapatillas para correr Pure Platinum Women Nike Air Max Sequent 3 para mujer .Zapatillas para correr Nike Air Max Sequent 3 para mujer | .nike roshe en blanco y negro, NIKE SPORTSWEAR AIR MAX 90 PREMIUM .De calidad superior Nike Air Max Flair 2017 Kpu negro / blanco para hombre / para mujer .Zapatillas Nike Womens Air Max 90 de avena Croc 443817 105 | .Nike Air Max 90 LX para mujer 898512 007 Gunsmoke Gray Luxe Running .Zapatillas de deporte Nike Wmns Air Max 90 LX para mujer NEW gunsmoke 898512 .Nike Free Run en color rosa y negro sin corte Tr Fit .nike flyknit zapatillas Nueva York, Kobe 8 sistema mc amarillo negro .Nike Nike Mujer gratis 5 Precio más barato en línea, 100% de alta calidad .Nike Air Max 90 Essential Villain Rojo Blanco Champagne Pink Pow Zapatos .Zapatos llamativos para mujer 5 blancos que entrenan con ajuste libre Nike Tr Breathe .Outlet Comprar Nike Free TR FIT PRT 5 Aquamarine Shops UK .Oferta Crystal Nike Free TR Fit 4 en línea, Crystal Nike Free TR .Ofertas en Nike Free TR 7 (negro / negro / gris oscuro) Women s Cross .zapatillas nike court royale tdv unisex baby low blanco blanco .Descuento Nike Air Max 96 para comprar una tienda outlet de EE. UU. | .Productos más nuevos, últimas tendencias y artículos más vendidos Nike air .Nike Nike free run 2 UK en línea, Nike Nike free run 2 tienda, venta por menor .Disfruta el descuento Nike Air jordan Shopping USA, el último oficial .nike air presto premium, descuento jordan 5 retro suede oregon packs .Hombres Nike Air Jordan 5 Gamuza Rojo Negro Gris .Air Jordan 4 (Iv) Retro Noble Fire Black Red White, nike .Nike Zoom KD 9 Blanco Negro Rojo Oferta [fautr 1330]: Retro .Nike Jordan Retro 1 Mujeres | .NIKE AIR JORDAN por qué no las zapatillas de baloncesto para hombre transpirable .Disfruta sin impuestos de venta en línea aquí Mujeres NIKE AIR MAX Venta caliente en línea .Zapatillas de baloncesto Nike Air Jordan 12 J12 en azul, blanco, rojo, niños altos .Mujeres nike Nike air jordan 13 tienda, mujeres nike Nike air jordan 13 .Mujer air jordan 4 retro gs columbia remasterizada para, nike roshe .Zapatillas Nike, Air Jordan 1 Retro Black White Outlet en línea .Nike MUJER Nike Air Max Tailwind más de moda, Nike MUJER Nike .nike sale running barato, Mujer Air Jordan 6 All Pink, zapatos nike .Zapatillas de baloncesto Nike más baratas al mejor precio | .2018 Air Jordan Shoes x Cheap Nike Air Jordan 13 Negro True Red .Descuento de venta Nike Air Jordan 13 Low Midnight Navy Zapatos de la NBA con .Nike Air Jordan 32 Deepblue blanco barato .Zapatillas de baloncesto Nike Zoom KD 9 Elite Racer Pink, 2017, mejor precio .Nike Nike air max 2017 barato | .Cómo Nike construyó HyperAdapt, la zapatilla de deporte con cordones de nuestros sueños .Nike Nike Free Run 3 Hombres Venta barata de moda, Nike Nike Free Run .Zapatillas de running Nike Zoom Terra Kiger 2 para mujer. .Nike Sneakers para mujer | .11 Razones para / NO comprar Nike Flex RN 2017 (agosto de 2018) | .Zapatillas de baloncesto Nike Preescolar para niños LeBron 15 | .Nike Free Green Hombres Jordan 11 Talla 7 a la venta | .11 Razones para / NO comprar Nike Free RN Flyknit (agosto de 2018) | .Zapatillas Hombre Nike Air Huarache Mesh Run Gris Naranja, sin tirantes .Nike Nike corriendo gratis 2 Mejor precio de descuento Outlet Compra en línea hoy .Auténticas Nike para mujer gratis para la venta Comprar Nike de la tienda en línea del Reino Unido .Zapatillas de running Nike Free V4 Barefoot verde blanco [Nike Shoes 0423 .
Time in Berlin
Time in Budapest
Time in Cape Town
Time in Hong Kong
Time in Kingston
Time in Kuala Lumpur
Time in Lagos
Time in London
Time in Los Angeles
Time in Madrid
Time in Milan
Time in Moscow
Time in New York
Time in Paris
Time in Phnom Penh
Time in Rio de Janeiro

67. Stüssy deporte x 67. Nike Air Huarache Light 19993 Las 100 mejores zapatillas de deporte de la 36f11f4 - site4you.online

Time in Rome
Time in Seoul
Time in Shanghai
Time in Sydney
67. Stüssy deporte x 67. Nike Air Huarache Light 19993 Las 100 mejores zapatillas de deporte de la 36f11f4
Time in Tokyo
Time in Toronto
Time in Vienna
Daylight Saving Time

“Spring forward and fall back.” This statement’s relation to time is known the world over and holds significant meaning, especially, for countries practicing daylight saving time (DST). Daylight saving time represents an adjustment in time by moving forward one hour to increase the length of daylight in the evening, generally during the summer time. The practice is used for the summer because it robs one hour of daylight at the start of the day, rendering it impractical in winter. However, for people who follow the world clock, there is an added hour of daylight after regular work hours to engage in “daytime” activities of choice.

Records prove the use of daylight saving time for roughly 100 years but archaeologists have found evidence that earlier in human history, the sun’s schedule was the basis for developing daily schedules. In the year 1895, a New Zealand scientist George Vernon Hudson proposed a two-hour shift forward in October and back in March in a paper to the Wellington Philosophical Society. Despite interest in the idea, it wasn’t carried out. However, in the year 1908, DST was used in Thunder Bay, Ontario, Canada and on April 30, 1916, Germany became the first country to do a whole scale implementation of DST.

Among the benefits daylight saving time is said to bring are the conservation of energy and fewer traffic accidents due to the presence of natural light during the time when traffic on the road is heaviest.

Time Zones Around The World

To calculate the time zone an area theoretically falls in, the measurement of the area’s longitudinal coordinate is divided by 15.  GMT was the same as Universal Time up until 1972. It is now a simple time zone. In 1847, the British railroads accepted GMT as a standard. It was calibrated using telescopes. The Meridian, after which GMT is named, is used to represent 0 degrees longitude (although it is not truly 0 degrees). Every place on Earth is measured either in degrees east or degrees west of this line.

The fact that time zones around the world are all calculated as an offset or difference from standard time makes it easy to know the time of a place by just knowing the time zone it falls in and the standard time at the current moment. Calculations can also be done using local time once the expected time difference is known. Most time zones are exactly one hour apart and their time is calculated as an offset from Coordinated Universal Time you can see this in our time zone map or by using our time zone converter to check the time difference between one location and another. Heading west of the Prime Meridian / Greenwich Meridian, time is earlier while heading in an easterly direction time is later. The International Date Line adds 3 to the total of time zones around the world. Additionally, several time zones are 30 and 45 minutes apart. Therefore, there are more than the theoretic 24 time zones around the world.

UTC (Coordinated Universal Time) / GMT (Greenwich Mean Time)

Greenwich Mean Time (GMT) is so named, because the longitudinal line after which it is named passes through Greenwich, London. Although GMT and Coordinated Universal Time (UTC) share the same time there is a fundamental difference between them. GMT is a time zone. It is used by some African and European countries. UTC on the other hand is a time standard. It serves as the foundation for time zones worldwide. Hence no country officially uses UTC as its local time. They both remain constant and are not affected by daylight saving time (DST) although some countries observing GMT use DST in the summer.

UTC serves as the basis for civil time. This standard is maintained using extremely precise atomic clocks along with calculations of the Earth’s rotation. This standard is maintained, synchronized and coordinated worldwide. UTC is determined by International Atomic Time (TAI) and Universal Time. TAI is a combination of the output of 400 extremely precise atomic clocks that provides the precise calculation of the speed at which our clocks should tick. Universal Time is the time it takes the Earth to complete a turn on its axis and is used to validate TAI against an actual Earth day.