Overview
- Member states at the General Conference on Weights and Measures voted on Thursday, October 15, 2026, to stop inserting leap seconds into Coordinated Universal Time and allow UTC to drift until a one‑hour correction is needed.
- The new continuous‑UTC system is scheduled to take effect on May 20, 2027, and will stop routine one‑second adjustments that have been used since 1972.
- Supporters say the change responds to real outages and risks from leap seconds and the prospect of a negative leap second, citing past incidents that affected sites such as LinkedIn, Reddit and Cloudflare and warnings from large tech firms.
- Practically, the vote eases short‑term burdens on computing, telecom and financial systems but requires astronomers, navigation services and operators of legacy systems — including some satellite providers that embed leap seconds — to adopt new procedures for the growing UTC–UT1 offset.
- Experts note the swap postpones frequent small fixes for centuries or millennia, leaves IERS and metrology agencies to monitor Earth rotation, and makes implementation planning and transition work the immediate priority before the May 2027 change.