Leap seconds have driven a raging debate in the metrological community for three decades. Now, that argument has been put to rest: The leap second is officially dead.

Doing away with an obscure metric the average person has been blissfully unaware of may seem like a novelty, but killing the leap second has major ramifications for technology you rely on every day. It also helps stave off what could’ve been a dangerous moment in time: The possibility of the world’s first negative leap second.

The International Bureau of Weights and Measurements (known by its French acronym BIPM) on Thursday said that in May 2027, it would stop issuing leap seconds to adjust what’s known as Coordinated Universal Time (UTC), 32 of which have been added since 1972.

The world implemented the leap second in 1972 due to a growing gap between time measured with atomic clocks and time based on the Earth’s rotation. The reason for the discrepancy? The latter is slowing down due in large part to tidal friction caused by the moon and Earth’s rotation not lining up. The molten core of the Earth as well as oceans and the atmosphere also affect the spin rate.

Leap seconds are a way to keep atomic-clock-driven UTC in line with astronomically kept Universal Time (UT1). Think of it like adding a little extra track for a train to keep running exactly parallel with another one. Rather than happening on a set interval—like a leap year—BIPM uses the average of hundreds of atomic clocks around the world and compares their time calculations to astronomical time to determine when a leap second is necessary.

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