BIPM votes to end leap seconds in UTC
Original: BIPM decides to stop adding leap seconds to UTC
Why This Matters
Ending leap seconds removes a known failure point for global digital infrastructure.
The BIPM's CGPM passed Resolution 5 (2026) to permanently stop adding leap seconds to Coordinated Universal Time (UTC), ending a 50-year practice of manually adjusting global clocks to match Earth's rotation.
The International Bureau of Weights and Measures (BIPM), through its General Conference on Weights and Measures (CGPM), has formally resolved to halt the addition of leap seconds to UTC. Resolution 5 of the 2026 CGPM marks the end of a practice introduced in 1972, under which leap seconds were periodically inserted into UTC to keep it aligned with UT1—the timescale based on Earth's actual rotational speed. The decision had been years in the making: the ITU and BIPM had debated the change since at least the 2010s, with the previous CGPM in 2022 agreeing in principle to abolish leap seconds by 2035. This resolution appears to formalize and advance that commitment. The core problem with leap seconds is their unpredictability and the risk they pose to modern digital infrastructure—GPS systems, financial networks, and internet protocols all struggle with one-second discontinuities. Tech giants including Google, Meta, and Amazon had previously adopted 'leap smearing' workarounds. The resolution does not immediately change how UTC is broadcast, but sets a clear international mandate to decouple civil timekeeping from astronomical observation.