Bob Ivry and Yuji Nakamura writing for Bloomberg:
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.
Anyone that’s had to deal with the nuances of dates or times knows just how complicated horology and chronometry are. Take for example the algorithm for determining leap years – there’s more to it than just adding an extra day to the calendar every four years. With intricacies like daylight savings, leap seconds, and time zones, it’s surprising that we don’t run into serious issues more often. What will you be doing with your extra second on June 30?