Making Time: How The U.S. Markets Were Affected By The Leap Second

Making Time: How The U.S. Markets Were Affected By The Leap Second June 30, 2015, started out as an ordinary day; it ended as one for the history books. That’s because a so-called “leap second” was added to the clock, making the last day of June this year a second longer than usual. It was the 27th such adjustment since the practice began in 1972.