When an entire second was added to clocks Tuesday, the anticipated network meltdown proved to be more feared than rampant, although it did cause several software glitches.
Major websites, including Instagram, Pinterest, Netflix and Amazon crashed during the time change, leaving many offline for around 40 minutes. Other software that rely on Amazon Web Services (AWS) also experienced malfunctions. AWS originally told NBC News that it believed the leap second was to blame, but later said the problem was rooted in an “internet connectivity issue.” Twitter users found the social networking site to have trouble estimating how long ago tweets were posted.
While this leap second is almost be negligible to the human eye, don’t be mistaken for its ability to obstruct computers all around the world.
Leap seconds are not completely unusual — there have been 26 since 1972 — but they have recently become a menace to technology, which calls for a 6-month notice in order for computers and software to adjust the time change beforehand.
When the last leap second was added in 2012, a number of high-profile websites, including LinkedIn, Reddit, Gawker, Foursquare and Yelp reported service disruptions. Even airports experienced some difficulty. The last leap second interrupted the reservation systems of global airline, Qantas Airways, causing flight delays.
While the leap second is used to keep the world’s official clocks in synchronization with the earth’s rotation, Tuesday’s edition was wrapped with both bad timing and a high risk. As Greece was due to repay its 2010 bailout loan to the International Monetary Fund, the worldwide financial market was put on a ledge.
Although officials provided more awareness to businesses, the leap second can also trigger unexpected problems, according to Linus Torvalds — the man who oversees the Linux computer operating system, which now owns many internet services and a large portion of Wall Street.
The team of scientists that decide whether to adjust the length of a day based on changes in Earth’s rotation said that it is the right thing to do.
“If we cannot manage to make our systems handle a leap second,” Udo Seidel with Amadeus Software told Wired , “then we have bigger problems.”
However, as more systems become interconnected, adding a leap second can make for a recipe of trouble. Information sent between a computer attuned for the leap second and a botched computer can result in mixed messages, disrupting both of the servers.
Many companies prepared for the leap second in their own ways. Some US exchanges closed the pay wall of certain trading markets, considering the millions that can be traded on global exchanges in any given second. Others, including Amazon and Google, “smeared” their systems. Dubbed as “leap smear,” this application disperses the extra second into tinier bits of time spread over the course of the day so when midnight hits, the time will be back into synchronization with Coordinated Universal Time (UTC).
Since most programmers didn’t consider a day longer than 86,400 seconds long, many systems don’t adjust to leap seconds. According to Demetrios Matsakis at the US Naval Observatory, a one-nanosecond (one billionth of a second) discrepancy on a GPS clock will result in an inaccurate location by a foot.
Such disastrous miscalculations have even led the US Naval Observatory — the official keepers of time in the US — to conceal the time for four hours after the leap second is placed.
When scientists began to establish ways to define a consistent measurement of a second, they came to agree upon an atomic standard in 1967. They decided that this would be the reliable constant measure that holds true for everywhere from then until the end of time.
Scientists knew that with such a precise definition of a second, we would inevitably dissociate with earth’s movement from time, although it was unsure whether the 86,400 second long day would end up being shorter or longer.
It was proved, many decades later, the length of a second was slightly shorter than the 1/86,400 of the average day.
Nearly every clock in the world calibrated accordingly to this definition of a second- from the Master Clock at the US Naval Observatory to clocks installed inside phones and automobiles. They compensated with a specified deviation time of 0.9 seconds from the rotation of Earth. This called for an occasional re-alignment from time to time of the UTC and Earth’s rotation.
It turned out to be necessary to insert seconds, rather than remove them, giving birth to the leap second.
The question raised by scientists is if the leap second is really necessary. The main reason of adding a leap second is seemingly for human perception- to make sure the clock strikes noon when the sun is at the highest point in the sky.
However, scientists argue it will take thousands of years for the rate at which time creeps away from the Earth’s rotation to become noticeable.
“There is this false correlation between the sun and time,” the supervisor of the world’s time standard, Elisa Felicitas Arias, said.
However, the fate of the leap second could come to an end this November at the World Radiocommunication Conference in Geneva, where it will be debated whether or not to continue the application.