On 30 June 2015 Google will slow down time. The so-called leap smear is possibly the most unique (probably because it’s the most well documented, because Google) response to the 26th instance of the Leap Second phenomenon. First implemented in 1972, the Leap Second is science’s remarkably unscientific answer to the slowing of the earth’s rotation. And so the time overlords over at the Earth Orientation Center of IERS Observatoire de Paris in France decreed an extra second to be added at the end of 30 June. When UTC clocks reach 23:59:59, instead of zeroing to start 1 July time will tick over to 23:59:60.
Earth’s rotation and the rising of the sun is our most basic concept of time and that is affected by the moon through tidal drag. Tidal drag – where the moon’s gravity causes the earth to bulge around the middle like your dad after Christmas lunch – is also being counteracted by the continents trying to spring back to their natural positions at the poles (because physics). So with earth’s rotation being so fickle, science turned to atomic decay as a measure of time.
What we have now is two (there’s actually a couple more) basic units of time that the world relies on: Universal Time (UT) based on the precise measurements of the earth’s rotation and International Atomic Time (TAI) that’s based on the atomic clock. Time as we civilians know it, however, is currently based on UTC (Coordinated Universal Time) that’s derived from TAI and corresponds with UT, but lags behind the atomic clock by a couple seconds. The lag is important and should remain constant, which calls for constant adjustment as the earth slows down.
With the rise of computers and time-based programing means that if a second is added to the clock, there’s an unknown outcome for data that exists in that second. In 2012, the last time a leap second was added, sites like Reddit and Foursquare went down. GPS is also another service that is severely affected. Google were smart and sliced up the second into milliseconds that were sprinkled over the course of the day, so when the clocks reach zero hour the system has already compensated.