| Author | Message | ||
Mental_sachinodu Hero Username: Mental_sachinodu Post Number: 19317 Registered: 10-2008 Posted From: 50.241.19.41 Rating: N/A |
that was before clocks were based on atomic frequency ... but now, US Naval observatory , Royal Observatory(Greenwich) both co-ordinated - hence the term UTC(Co-ordinated Universal Time) | ||
Asdf Megastar Username: Asdf Post Number: 24979 Registered: 12-2014 Posted From: 76.109.163.196 Rating: N/A |
greenwich anukunna | ||
Mental_sachinodu Hero Username: Mental_sachinodu Post Number: 19316 Registered: 10-2008 Posted From: 50.241.19.41 Rating: N/A |
if anyone here shouted screamed "Happy New Yearrrrr" when the clock struck 12:00 midnight, you might have been a second early.  just found that an extra second was added to our clocks at 11:59:59 on december 31st this is from a US Naval Observatory article, who manage the master clock On December 31, 2016, a “leap second” will be added to the world’s clocks at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC). This corresponds to 6:59:59 pm Eastern Standard Time, when the extra second will be inserted at the U.S. Naval Observatory’s Master Clock Facility in Washington, DC. Historically, time was based on the mean rotation of the Earth relative to celestial bodies and the second was defined in this reference frame. However, the invention of atomic clocks defined a much more precise “atomic” timescale and a second that is independent of Earth’s rotation. In 1970, international agreements established a procedure to maintain a relationship between Coordinated Universal Time (UTC) and UT1, a measure of the Earth's rotation angle in space. The International Earth Rotation and Reference Systems Service (IERS) is the organization which monitors the difference in the two time scales and calls for leap seconds to be inserted in or removed from UTC when necessary to keep them within 0.9 seconds of each other. In order to create UTC, a secondary timescale, International Atomic Time (TAI), is first generated; it consists of UTC without leap seconds. When the system was instituted in 1972, the difference between TAI and UTC was determined to be 10 seconds. Since 1972, 26 additional leap seconds have been added at intervals varying from six months to seven years, with the most recent being inserted on June 30, 2015. After the insertion of the leap second in December, the cumulative difference between UTC and TAI will be 37 seconds. |