Edited by mbhcsf at 11-1-2021 04:02 PM
ni bagaimana ukuran masa dalam JAM sehari dilakukan
TimeandDate.com explained how the difference is calculated: To determine the true length of a day, IERS scientists determine the exact speed of the Earth's rotation by measuring the precise moments a fixed star passes a certain location in the sky each day. This measurement is expressed as Universal Time (UT1), a type of solar time.
UT1 is then compared to International Atomic Time (TAI), a highly precise time scale that combines the output of some 200 atomic clocks maintained in laboratories around the world.
The true length of a day is expressed by the deviation of UT1 from TAI over 24 hours.
When UTI and TAI differ by more than 0.9 seconds, the IERS can add or subtract a "leap second" from the world's clocks to keep them in sync, National Physical Laboratory Director Dr. DK Aswal told The Weather Channel.
So far, the IERS has only added leap seconds: 27 since 1972, to be exact. The last one was added on Dec. 31, 2016. But this could soon change. "IERS has decided that no 'leap second' would be added to the world's official timekeeping in December 2020, indicating that Earth is rotating faster than it has in 50 years.
If the Earth's rotation keeps accelerating, the world's first negative leap second can be announced by IERS in the future," Aswal told The Weather Channel.
But while adding or subtracting leap seconds is important for satellites, it can have a negative impact on other forms of communication. When a leap second was added in 2012, websites including Reddit, Yelp and LinkedIn crashed, according to The Telegraph. | 
Post time 11-1-2021 03:51 PM
cisss...
