The International Bureau of Weights and Measures has approved the elimination of the leap second, a periodic adjustment that keeps official timekeeping synchronized with Earth's rotation. The change takes effect on May 20, 2027—moved up from an initially planned 2035 date.
The leap second system has long posed challenges for digital infrastructure. Past adjustments have triggered outages across major services including Reddit and LinkedIn. The accelerated timeline stems from a specific risk: future corrections might require removing a second entirely, an unprecedented scenario that could destabilize computer systems worldwide. Tech giants including Meta, Google, Microsoft, and Amazon backed the elimination for this reason.
After 2027, the difference between official time and Earth's actual rotation will drift gradually. It could take roughly 3,000 years for that gap to accumulate to a full hour—a timeline so distant that no immediate correction will be necessary. This shift represents a fundamental change in how humanity measures time, moving away from astronomical adjustments toward a purely atomic standard.