This weekend was not the best one for big websites and online services in terms of their uptime. As we reported on Saturday, massive thunderstorms in the northeastern portion of the US managed to knock out Amazon's cloud servers in northern Virginia. That caused services such as Netflix, Instagram and more to be shut down for a long period of time.
Now it appears other websites suffered some outages on Saturday afternoon and evening, but they were not caused by the weather. BuzzFeed.com reports that the culprit was a bug in those sites caused by the "leap second". This extra second is added on occasion to the official atomic clocks around the world so that the official time stays locked in with the speed of the rotation of the Earth, which is actually slowing down.
Unfortunately, the databases of some major websites such as Reddit, Foursquare, LinkedIn and others didn't take that "leap second" into account and got hit with a bug that caused them to go down for various amounts of time. All of those sites and services are now back up and running. Hopefully they will go over their databases again and prepare for the next "leap second event".