The Earth's gradually slowing rotation can sometimes fiddle with our clocks, reportedly creating a need for an extra second to be added to keep things synchronized across the globe.
In New York, at 6:59:60 p.m., a so-called "leap second" will be added to keep the common worldwide time standard -- Coordinated Universal Time (UTC) -- in sync, according to Timeanddate.com.
Leap seconds have occurred 25 times since 1972, and though typically benign, they have the potential to disrupt industries reliant on computer systems, like tech companies and stock exchanges, according to a report by The New York Times.
Adding just one second, the Times reports, has the potential to cause entire computer operations to fail. In 2012 -- the last time a leap second was added -- websites like Foursquare, Reddit and LinkedIn all experienced interruptions, the report said.
According to The New York Times, markets have taken precautionary measures in case of any disruptions, like ending after-hours trading and resetting clocks ahead of time.
According to Time and Date's report, the need for a leap second works like this: UTC is the most common time standard used to synchronize clocks across the world. Two time standards make up UTC: Atomic Time and Universal Time.
Atomic time is the most accurate time scale on Earth. It uses highly precise atomic clocks that provide "the exact speed for our clocks to tick," the report said.
Universal Time, on the other hand, measures the Earth's rotation to determine the length of a day. It is not as consistent as atomic time.
When the difference between the two time standards reaches 0.9, a leap second is added to keep UTC in sync throughout the world.
Clocks "are effectively stopped for that second to give Earth the opportunity to catch up with atomic time," the report explained.
Spencer Kent may be reached at skent@njadvancemedia.com. Follow him on Twitter @SpencerMKent. Find the Find NJ.com on Facebook.