The extra second has the potential to cause computer glitches. Image Credit: sxc.hu
World time authorities are preparing to add an extra second to the clocks at midnight on June 30.
Tomorrow night a 'leap second' will be officially added to the world clock so that at 11:59:59 the time will temporarily hit 11:59:60 as the transition from one day to the next is delayed by one second.
"Earth’s rotation is gradually slowing down a bit, so leap seconds are a way to account for that," said Daniel MacMillan of NASA’s Goddard Space Flight Center in Maryland.
The last time a leap second was added was exactly two years ago on June 30 2012.
While the transition is expected to go mostly without a hitch there is the possibility that some computer systems will experience technical difficulties due to the unconventional change in time.
"There are consequences of tinkering with time," said research scientist Peter Whibberley.
"Because leap seconds are only introduced sporadically it is difficult to implement them in computers and mistakes can cause systems to fail temporarily. "
An in-depth explanation of the whole concept of a leap second can be viewed below.