While many people will be counting down the seconds to ring in the new year, they’ll have to make room for an extra one.
Official clocks around the world are adding the extra second just before midnight universal coordinated time (UTC), or 6:59:59 EST.
As a result of the rotation of Earth — which slows ever so slightly over time — clocks have to be adjusted periodically.
While adding a second might seem like a trivial matter, that addition is crucial in the accurate operation of satellites. If the timing is off, over time it could cause satellites to slam into each other.
Since 1972, 26 leap seconds have been added to our clocks. The most recent addition was on June 30, 2015.
However, there’s been some controversy surrounding the addition of the occasional leap second. Just last year, the United Nations International Telecommunication Union announced that a decision over whether or not to keep the extra second would be postponed until 2023.
There are many who believe that additional second is more trouble than it’s worth: in 2012, that extra second created havoc. Websites such as Mozilla, Amazon, LinkedIn and even airline reservation systems crashed just after midnight UTC.
However, the argument is that, because Earth’s rotation is slowing down by about two thousandths of a second each day, over a long time span, atomic clocks — high-precision clocks around the world that are used in devices such as GPS satellites — would be greatly mismatched with Earth clocks.
But for now, consider this: you get to sleep in an extra second on New Year’s Day.