A Second from Disaster: Leap Second Added to Time Caused Web Crash

Who would have thought a mere second could cause so much trouble?

Some of the world's most popular web sites crashed on Sunday after a "leap" second was added to the clock by international timekeepers, it has been revealed.

Sites such as Reddit, FourSquare, Yelp, LinkedIn, Gawker and StumbleUpon all experienced problems simultaneously on Sunday after the extra second was added to Universal Coordinated Time (UTC). The extra blip in time played havoc with the sites' source code and also caused servers to crash, leaving the sites down and unaccessible for hours, experts reveal. 

The extra second is added to UTC—the benchmark time agreed internationally—every few years to keep it in line with the time as determined by the wobble in the Earth's rotation.

Working on the assumption that every minute always lasts 60 seconds, computer applications tend to go haywire when an extra leap-second is inserted into the code, much like the problem computer programers faced during the dreaded "Y2K" debacle over a decade ago.

The sites were back up and running later on in the day, after tech experts sorting through the problem.