In 2012, a leap second brought about a number of website outages all over the Internet. So brace yourselves, because the Paris Observatory has announced that June 30, 2015 will bring us another one. On that day, clocks will read 11:59:60 PM.

Image: prague town hall clock by Kainet/flickr/CC BY 2.0

The keepers of time in France have announced that, for the 26th time since the first instance in 1972, a leap second will be added to this year. This compensates for the slight slowing of the Earth that atomic clocks take into account. Adding the second keeps the Coordinated Universal Time (UTC) in step with atomic time.

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According to The Telegraph, events like the turmoil of three years ago has made leap seconds more controversial:

The US wants to get rid of leap seconds claiming they're too disruptive to precision systems used for navigation and communication. At a conference in Geneva in 2012 delegates argued that precisely timed money transactions could go astray or vehicles could be sent tens of metres out of position if they are a second out in their measurement of time

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.

It would also spell the end for Greenwich Mean Time, which is measured by the time at which the Sun crosses the Greenwich Meridian and was adopted in Britain in 1847

Experts also 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.

Rory McEvoy, Curator of Horology, Royal Observatory Greenwich adds that the argument about getting rid of the leap second may actually resolved this year, after 12 years of debate.