Leap Second: Extra Second Being Added to World's Atomic Clocks Saturday Night

Posted on June 29, 2012

Reuters reports that an extra second is being added to Earth's clocks Saturday evening. Reuters says the world's atomic clocks will read 23 hours, 59 minutes and 60 seconds on Saturday night before moving to midnight Greenwich Mean Time. In the U.S., the leap second will occur just before 8 p.m. EST.

Space.com reports that astronomers have discovered that the Earth's rotation is slowing down very slightly, and the Earth has been falling behind atomic time at a rate of two milliseconds per day. The extra second will help make up the difference.

The U.S. Naval Observatory (USNO) is charged with the responsibility for precise time determination and management of time dissemination in the U.S. The USNO Master Clock is based on a system of dozens of independently operating cesium atomic clocks and a dozen hydrogen maser clocks. You can the website for the Master Clock and find the current accurate time here.

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