Typically, leap seconds are added every two or three years, although the last one was inserted just 18 months ago in June 2015. Some years, the Earth runs bang on time and no adjustment is needed. It is also possible for a second to be removed from the UTC (Universal Co-ordinated Time) timescale, although this has never happened.
BT’s speaking clock will add a second’s pause before its third pip and Radio 4 will also add an extra pip to its 1am bulletin.
But there can be consequences of tinkering with time. When a leap second was added in 2012, Mozilla, Reddit, Foursquare, Yelp, LinkedIn and StumbleUpon all reported crashes and there were problems with the Linux operating system and programmes written in Java.
Because leap seconds are only introduced sporadically, it is difficult to implement them in computers and mistakes can cause systems to fail temporarily.
Many computing systems use the Network Time Protocol, or NTP, to keep themselves in sync with the world’s atomic clocks. But most are not programmed to deal with an unexpected extra second.
refers to as a “leap smear” and has been gradually adding milliseconds to its system clocks prior to the official arrival of the leap second.
The US wants to get rid of leap seconds, claiming they are 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 World Radiocommunication Conference was due to decide on the fate of the leap second at last year’s meeting, but has deferred the decision until 2023.
Read more at www.telegraph.co.uk
