Understanding the leap second that crashed the Internet

You may have noticed yesterday that io9 — and the rest of the Gawker network — went down for several minutes yesterday. Other sites, including Reddit, 4Chan, LinkedIn, The Pirate Bay, Yelp, and Meetup, had lengthy outages, all at the hands of one tiny unit of time. But how did a single leap second fell these websites?

At midnight Greenwich Mean Time (5pm PT/8pm ET), we added an extra second to our coordinated universal time, the time standard the world uses to determine what time it is. This is to compensate for inconsistencies in the Earth's rotation. This is only the 25th time that we've made such an adjustment since the 1970s, and the first time since 2008. With our ever-changing technological systems, some applications simply weren't properly prepared for the adjustment, resulting in widespread outages.

Edit: In the comments, 99TelepodProblems linked to a helpful article on Wired that notes that many systems use the Network Time Protocol to keep themselves in sync with the world's atomic clocks, which entered the extra second. The Wired piece is definitely worth a read.

This is completely unconnected to last night's outage of sites served by Amazon's Elastic Compute Cloud US East servers (including Netflix, Instagram, Pinterest, and SocialFlow), which were caused by an electrical storm that knocked out the power to those servers. It has just been a weird weekend for the Internet.

For more about leap seconds and whether it's time to do away with them for good, check out our previous coverage of these persnickety temporal exceptions:


Understanding the leap second that crashed the InternetWhen does a minute last 61 seconds?

On this coming Sunday June 30, intrepid horologists from around the world will daringly attempt to hold back the relentless onslaught of time. Well, to be fair it won't actually be that difficult. July 1st is scheduled to start an entire second later than it should, a feat of temporal distortion that will be accomplished by making the final minute of the month last 61 seconds. More »


Understanding the leap second that crashed the InternetHow the "Leap Second" Really Works

According to the brainfarm at ABC, the Earth is "out of sync with time." That's how they explain the 2008 "leap second" in this segment. I also appreciate the way the newscaster clarifies that the "leap second is like a leap year - only shorter." Seconds are shorter than days! Good to know. More »


Understanding the leap second that crashed the InternetIs it time to do away with leap seconds?

For decades, the world has relied on incredibly accurate atomic clocks to keep time; but atomic clocks are much more consistant than the rotation of the Earth, which varies in speed ever-so-slightly as it spins about its axis. Consequently, every few years, the time based on the Earth's rotation falls out of sync with time kept by atomic clocks. More »


So, leap seconds: threat or menace? Discuss.

Photo credit: MR.LIGHTMAN/Shutterstock.