It has been said that at 2359 Greenwich Mean Time on June 30, or 9.59am AEST on July 1, the world will have a minute of 61 seconds.

Experts call this event as the leap second. This is an event during which the timekeepers adjust high-precision clocks so that they could be in sync with earth's rotation, which is affected by the gravitational pull of the sun and the moon.

This additional second might not be important for all, but for horologists, the additional second is a big deal. There is an argument in the community as to whether it is vital or should be scrapped. The last modification took place on June 30, 2012, and it was disruptive for many internet servers, including Qantas' online reservation system, which went down for several hours.

The leap second is not something that needs to be added to the clock on your mantelpiece. Instead, its importance is for super-duper timepieces, especially those using the frequency of atoms as their tick-tock mechanism.

Above the atomic clock range are 'optical lattices' that uses strontium atoms. On the other hand, caesium and rubidium clocks are the workhorses of Global Positioning System satellites, which have to send synchronised signals so that sat-nav receivers can triangulate their position on earth.

On earth, big-data computers may be less manic than atomic clocks, but still need highly precise internal timers. Since 1971 there have been 25 occasions when the leap second was added in an effort to simplify Co-ordinated Universal Time (UTC), the official moniker for GMT.

But now from past 15 years, a debate has intensified about whether the change should be made, given the hassle. Daniel Gambis, from the International Earth Rotation and Reference Systems Service, which has the authority to saying whether the second should be added, has defended the change.