We can celebrate New Year’s Eve one second longer as a leap second will be added on December 31, 2016, the U.S. Naval Observatory stated on July 6. Timekeepers at the International Earth Rotation and Reference Systems Service explain that the leap second is needed to fill the gap between the time it takes for Earth to spin on its axis and the time on atomic clocks, our most accurate clocks independent of the planet’s rotation .

Apparently, the Earth’s spinning is slowing down and to keep the time on computers on track, we need to adjust the time.  In this case, the Coordinated Universal Time will go to 11:59:60 instead of 11:59:59 on December 31.

The decision as to when to add a leap second is dictated by the IERS. Since 1972, 26 additional leap seconds have been included at intervals ranging from six months to seven years. The latest addition of a leap second was on June 30, 2015.

leap second

An atomic clock at the National Institute of Standards and Technology (NIST). Credit: NIST

Geoff Chester, a spokesman for the US Naval Observatory, cites that 10 percent of computer networks around the globe fail every time a leap second is included. In 2012, when a worldwide booking system malfunctioned due to inconsistency between its own time and time from outside systems, the flight got delayed for several hours. This incident also affected social media sites like Reddit and Instagram as well  as Netflix and Yelp, National Geographic reports.

Keeping accurate time does not only affect things here on Earth. It can also have huge implications to operations outside the planet.

“Think about Juno in orbit around Jupiter,” adds Jean Dickey, a  physicist at the Jet Propulsion Laboratory. “With all our antennas on Earth, an error in time means an error in Earth rotation, which would end up being a navigation error. It could really wreak havoc with the mission.”

Interestingly, the  US government wanted to remove the leap second. However, the International Telecommunications Union (ITU) voted to continue the practice in 2015. Experts at ITU say more investigations are still needed before making drastic decisions.