ITU Updates Global Precision-Time Guidance; UTC Becomes Continuous in 2027

The International Telecommunication Union released its first comprehensive update of global precision-time guidance since 1997 on October 30, 2026. Two weeks earlier, the International Bureau of Weights and Measures agreed to make Coordinated Universal Time continuous starting May 20, 2027, ending future leap-second insertions. While these changes improve the common reference clock, they do not keep delayed observations current. The update also highlights a new risk where AI systems could make decisions based on obsolete data if they act faster than evidence ages.

These technical decisions determine how modern economies maintain a common sequence of events. The guidance requires that critical-infrastructure procurement mandate tested timing integrity, including evidence age and safe behavior under failure. This shift means AI-driven systems must know when the evidence supporting a decision has become too old to trust.