Today the 30th June 2015, at midnight clocks will pause momentarily as the entire planet gains a bonus second. If you are gazing at the dial on an atomic clock, it will read 23:59:60 before ticking forward to 00.00.00. The addition of a “leap second” is designed to sync the Earth’s rotation, which is gradually slowing, to catch up with atomic clocks, by keeping the official time neatly in sync with night and day.
“There are consequences [to] tinkering with time,” said Peter Whibberley, a senior scientist at the National Physical Laboratory, which is responsible for defining the Greenwich Mean Time. “Because leap seconds are only introduced sporadically it is difficult to implement them in computers and mistakes can cause systems to fail temporarily.”
Dr Leon Lobo, business development manager at NPL, who is involved in the preparations for today evening said, “If everyone adds the second in the same way at the same time it shouldn’t cause problems. But if some apply it in a different way or at a slightly different time, you start to have discrepancies in the time that people have. That’s when things trip up.”
Dr Marek Kukula, public astronomer at the Royal Observatory, Greenwich said, “We’re all uncomfortable with the idea of our clocks being out of sync with the night and day cycle - it’s a psychological thing.”
Since 1967, when clocks went atomic, human timekeeping has become independent of the earth’s rotation. The problem is, the planet is slowing down and clocks are not. So every few years, scientists add a second, to get everything back in sync,. They’ve done it 25 times since 1972. The last time was in 2012, but that was on a weekend. Mozilla, Reddit and LinkedIn all of them crashed. More than 400 flights were grounded as the Qantas check-in system went down in Australia, requiring the job to be done manually.
June 30 will be the first leap second during trading hours since markets went electronic. About 10 percent of the large-scale computer networks will have hiccups due to the leap second, said Geoff Chester, public affairs officer for the U.S. Naval Observatory in Washington.
The US and France are pushing to abolish the leap seconds phenomena, with Britain, Russia and China arguing that the technical challenges are manageable. “We have always taken the Earth’s rotation as the ultimate reference for timekeeping and astronomers and navigators still make use of it,” said Whibberley. “We shouldn’t break the link without carefully weighing the consequences.”