# CGPM sets continuous UTC to take effect on 20 May 2027

_Published Thursday, October 15, 2026 at 12:50 PM EDT · Infrastructure, Policy · Latest · Tier 1 — Major_

The General Conference on Weights and Measures has decided that continuous Coordinated Universal Time will take effect on 20 May 2027, bringing forward the transition previously set for in or before 2035.

The resolution sets the maximum difference between UTC and Earth-rotation time at 3 600 seconds, or one hour, to preserve continuity for several centuries. It cites synchronization needs across transportation, energy distribution, telecommunications and space systems.

A workshop estimated a 30 % probability of a negative leap second by 2035. The resolution says critical infrastructure is largely unprepared for that previously unused adjustment.

## Sources

- [bipm.org](https://www.bipm.org/en/cgpm-2026/resolution-5)

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Canonical: https://techandbusiness.org/newswire/x5y53UQDYdxI9tkba1QtHt
Published: 2026-10-15T16:50:26.212Z
Story chronology: 2026-10-15T16:11:36.000Z
Retrieved: 2026-10-15T20:20:28.990Z
Publisher: Tech & Business (techandbusiness.org)