By Ed Zwirn
Originally published on June 28, 2015 in the New York Post.
If it seems like summer days are lasting longer than ever, it may not be your imagination. The last day of this month will last exactly one second longer, a fact that has sent financial markets and software developers in general into a mad rush to slow down.
Owing to the slight disparity between the speed that Earth actually revolves around the sun and the atomic clocks used to set Coordinated Universal Time, a 61st second will be added to the last minute of the official day on June 30. This “leap second” will occur as the clock strikes 8 p.m. in New York.
The last time this happened was in 2012, and, according to John Lowe of the National Institute of Standards and Technology, “a whole bunch of Web sites” went down as a result.
Among the reported casualties over that weekend were the electronic reservation system for Qantas Airways, and Web sites such as LinkedIn, Reddit and Yelp.
Unlike the last leap second, the coming one will occur in the middle of the trading week, smack between the winding down of Tuesday’s futures trading and the start of Asia’s Wednesday business.
And while most US financial markets are supposed to open and close as scheduled during the affected period, CME Group’s Globex commodities trading system will see a delayed opening.
In the broader online business world, the software mavens have installed a variety of patches. Google, for example, says it plans to “smear away the extra second” by spreading it out over a 20-hour window during which it will slowly sync all its server clocks.
“At the end of the smear window, the entire leap second has been added, and we are back in sync with civil time,” Google explained in a recent blog.
Lowe acknowledges that the impact of possible leap-second-induced disruption has only become “more of an issue” as the pace of business and trading has quickened over the years.
“It’s like a mini-mini-miniature Y2K,” he said. “Everybody knows this is coming.”
The New York Stock Exchange will add the leap second before opening for trading Wednesday morning.