June 30, 2015 - The day with the leap second
"With 61 Seconds in a Minute, Markets Brace for Trouble"
"Since 1967, when clocks went atomic, human timekeeping has been independent of the earth's rotation. The problem is, the planet is slowing down and clocks are not. So every few years, to get everything back in sync, scientists add a second. They've done it 25 times since 1972. The last time was 2012, but that was on a weekend. June 30 will be the first leap second during trading hours since markets went electronic."
"It's scheduled for 8 p.m. in New York, just when markets in Asia are opening, and exchanges around the world are taking no chances. U.S. stock markets are ending some after-hours trading early and others from Sydney to Tokyo are recalibrating their clocks ahead of time. "
"To lessen any possible impact of the leap second, NYSE Arca Equities said evening trading will close five minutes early; Nasdaq will stop trading at 7:48 p.m. New York time and shut down at 7:55 p.m.; Intercontinental Exchange Inc. said it's delaying all market transitions; CME Group Inc. said any data files submitted between five minutes before and after the leap second will be held for processing till five minutes after.
The extra second is coming amid a critical week for global investors, with Greece's debt crisis worsening. June 30 is the day when the nation's current bailout is set to expire and when a payment to the International Monetary Fund is due.
Futures exchanges in Australia, Singapore, South Korea and Japan will smear the leap second after the event, according to FIA. The Japanese stock exchange will smear the leap second over a period of two hours beforehand, so when the leap second comes just before the market opens, the exchange will be synchronized."