Computers and the networks they create are all very logical, and dependent on a number of unchanging standards to function. However, the universe sets its own rules and operates on a logic all its own. This year, we will have exactly one extra second of time with 31,536,001 seconds instead of the usual 31,536,000--and this presents a big problem for computers.
To compensate, the Paris Observatory has announced that it will be add an extra second to clocks on June 30. This extra second, popularly known as a leap second, isn't that big a deal to us humans but for computers this presents a huge challenge. Imagine, if you will, if every computer in the world was suddenly off by one second.
This problem is going to cause so many ramifications for computer systems worldwide that many software companies are already preparing for the issues.
How did this happen? While Atomic time is constant, the rotation of the Earth is actually slowing by 2000ths of a second every day. This slowdown means there will be an extra second in 2015. The extra second is added to the universal coordinated time (UTC) so that it matches the atomic time created a problem much like the Y2K bug that affected computers at the turn of the century.
On June 30, 2015, the clock will read 11:59:60 and this will cause issues with many computer systems which are not programmed to handle the time. As many systems are dependent on precise time, issues are expected as many systems simply aren't capable of handling that one extra second.
This is not the first time this problem has occurred. In total, 25 leap seconds would have been added to the time over the last 40 years. In 2012, systems such as Mozilla, Foursquare, LinkedIn, Reddit and StumbleUpon all reported issues when a leap second was added.
Google, however, has developed its own system for handling the time so its services don't go out. Instead of adding one second, the technique known as "leap smear" breaks the second into milliseconds and gradually adds the milliseconds to its clock.
"When it became time to add an extra second at midnight, our clocks had already taken this into account, by skewing the time over the course of the day. All of our servers were then able to continue as normal with the new year, blissfully unaware that a leap second had just occurred. We plan to use this 'leap smear' technique again in the future, when new leap seconds are announced by the IERS," Google's Site Reliability Engineer, Christopher Pascoe says.
Later this year a final decision will be made on whether or not the leap second should be abolished. Until that time, the leap second will continue to problem for software all over the world.
