For those who believe that every second counts, this story is for you, because the year 2016 got an extra second added to it. That second, referred to as a "Leap Second" was added right as 2016 turned to 2017 — or at 23:59:59. Instead of the atomic clocks jumping to 00:00:00, they officially stood at 23:59:60.
This was done to keep time as precise as possible, much like the reason we add a Leap Day once every four years.
Leap seconds are added to compensate for the fact that Earth's rotation is gradually slowing down, and to make sure that our precise clocks remain in sync with how long a day lasts on Earth.
"This extra second, or leap second, makes it possible to align astronomical time, which is irregular and determined by Earth's rotation, with Coordinated Universal Time (UTC) which is extremely stable and has been determined by atomic clocks since 1967," noted the Paris Observatory in France in a statement. The Observatory houses the International Earth Rotation and Reference Systems Service (IERS), which is responsible for synchronizing time.
While Leap Days are predictable, Leap Seconds are sporadic. In fact, over the past 45 years, we have added a Leap Second 27 times. The less predictable nature of the Leap Second makes it virtually impossible to build into a watch or clock.
For those who want more information about the Leap Second, universal time, the evolution of GPS and satellite timing, we suggest you take a look at the extensive report by Jack Forster of Hodinkee. You can read his story at this link.
Credit: Image by NASA.gov.