The International Earth Rotation and Reference Systems Service has issued Bulletin C 72 confirming that no leap second will be added at the end of December 2026. The announcement, signed by Christian Bizouard at the Observatoire de Paris, maintains the current UTC-TAI offset of -37 seconds that has been in place since January 1, 2017.

Leap seconds are inserted to keep Coordinated Universal Time aligned with Earth's irregular rotation, measured as UT1. The IERS evaluates this discrepancy every six months and announces adjustments for June or December. Since the last leap second was added on December 31, 2016, the cumulative offset has remained stable at 37 seconds.

This stability simplifies operations for systems that depend on precise time synchronization. Financial trading platforms, GNSS receivers, and distributed databases avoid the complex handling required during leap second events, which have historically caused outages at major cloud providers and trading venues.

The next opportunity for a leap second arrives in June 2027, though Earth's rotation has been accelerating slightly in recent years, making further additions unlikely. Engineers should still design systems to handle both positive and negative leap seconds, as the long-term trend remains unpredictable.