What does «Tiempo Universal Coordinado» mean in Spanish?
- Coordinated Universal Time (abbreviated UTC) is the basis for standard time in time zones around the world. It is a compromise between a time measurement based solely on an atomic clock and one based solely on the rotation of the Earth. Because the day is defined exactly as 86,400 seconds (where the second is defined in terms of a physical property of atoms of the element cesium), but the Earth takes about 86,400.002 seconds to make exactly one rotation, time kept solely according to an atomic clock would eventually get out of sync with the time measured by astronomical observations. But to keep time strictly according to the Earth's rotation period - which varies slightly from day to day - would require resetting clocks by small fractions of a second each day. As a compromise, UTC, introduced in 1972, is defined to never be more than 0.9 seconds behind or ahead of the time determined by astronomical observation (called Universal Time, UT or, unofficially, Greenwich Mean Time).