Leap seconds are therefore essential to ensuring civil time does not drift away from time based on the Earth's spin. If not corrected, such a drift would eventually result in clocks showing the middle of the day occurring at night.
While it would take hundreds of years for the difference to become obvious to most people, astronomers and celestial navigators rely on time being consistent with the conventional positions of the Sun, moon and stars to within a fraction of a second. ...
The US wants to get rid of leap seconds claiming they're too disruptive to precision systems used for navigation and communication. But Britain opposes the change, saying that it would forever break the link between our concept of time and the rising and setting of the Sun.
Experts fear that once this link is broken it could never be restored because although the Earth's timekeeping systems are built to accommodate the occasional leap second, adding a leap minute or hour to global time would be virtually impossible.
The fate of the leap second is expected to be decided at the World Radiocommunication Conference in November 2015.
