"Leap Second" on June 30th may cause worldwide internet crash


The extra second will take place at 8 p.m. ET on June 30 (Pakistan Time: 1 July 2015, 04:59:60) so that we can sync up our watches with the Earth's slowing rotation. But the 61-second minute threatens to make computer systems go haywire, potentially screwing up complex trades that can take place in a split second.

What is Leap Second ?

The “leap second” attempts to rectify this by inserting an extra second into a day to give the Earth time to “catch up” to where it’s supposed to be based on the traditional solar cycle. The leap second was established as an international standard in 1972, and there have been 25 such seconds added since that year.
“Earth’s rotation is gradually slowing down a bit, so leap seconds are a way to account for that,” NASA's Daniel MacMillan

Why is it a problem for computers ?

The system works fine for humans because we can just accept the extra second and essentially ignore it. But computers are programmed to have 60 seconds in a minute Period. If you tell a computer that there’s going to unpredictably be an extra second in certain years, it will laugh at you. That is to say it will glitch because it can't complete its normal operations.

For computers, a day is 86,400 seconds, no matter what. When you try to introduce an extra second that doesn’t fit into the normal format of time (the official leap second timestamp on June 30 will be 23h:59m:60s), it can throw off computer systems’ processes.

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What’s the worst that could happen ?

Before, leap seconds have created blackouts at prominent sites, for example, Reddit, Yelp and Foursquare. A 2012 leap second even prompted 400 flight defers in Australia, driving air terminal laborers to lead registration by hand as opposed to utilizing PCs. Then again, specialized glitches identified with the jump second are generally segregated. There's minimal shot of a substantial scale mechanical shutdown. However, the way that individuals invest so much time online now implies specialized issues identified with the leap second could influence a greater number of individuals than before.

Is there a way to stop these problems ?

There are a few solutions. Google uses a trick it calls the “leap smear,” in which a millisecond or two is added to computers’ clocks gradually over the course of a day so computers add the additional second without noticing.

Leap seconds are necessary because the length of a day and year is in constant flux. Earthquakes and volcanic eruptions have a tendency to slow down the Earth's rotation, as do gravitational forces from the Moon and other celestial bodies.

How should you spend your precious extra moment on Earth? Comedian John Oliver has a few ideas:

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Previous Leap Second: THE INSIDE STORY OF THE EXTRA SECOND THAT CRASHED THE WEB


VIA:TIME and The Washington Post