Friday 16 October 2026
Evening Edition
ZOTPAPER

News without the noise

ZOTPAPER
Science

Global timekeepers vote to scrap leap second, advancing change to 2027

Decision aimed at preventing infrastructure failures is brought forward from the 2035 timeline

By LineZotpaper
Published
Read Time1 min
The International Bureau of Weights and Measures (BIPM) has voted to abolish the leap second, the occasional adjustment used to keep official time aligned with Earth's rotation. The change, previously planned for no later than 2035, has been expedited and will take effect on May 20 next year.

The BIPM's decision, announced on Thursday, retires the leap second earlier than originally scheduled. Members had agreed in 2022 to stop using leap seconds on or before 2035, but the proposal has now been accelerated to align with World Metrology Day on May 20, 2027.

The leap second is an ad hoc adjustment occasionally added to coordinated time standards so they reflect the Earth's real, and inconsistent, rotation. The vote aims to prevent potential infrastructure failures similar to the Y2K bug scare, according to the BIPM's published proposal.

The full reasoning behind the expedited timeline was not detailed in initial reports, though the decision marks a significant shift in how global timekeeping will be maintained.

§

Analysis

Why This Matters

  • The leap second has long been a source of difficulty for computer systems, which are built around steady, predictable time.
  • Removing it reduces the risk of clock-related failures in networks, financial systems, and other infrastructure.
  • The new timeline takes effect within months, giving operators less time to adapt than the original 2035 target allowed.

Background

The leap second was introduced decades ago as a way to keep civil time, based on atomic clocks, reasonably close to astronomical time, based on the Earth's rotation. Because the planet's spin is uneven, occasional corrections have been needed over the years. The adjustments have disrupted computing systems, and the timekeeping community has debated whether they are worth keeping. After years of discussion, BIPM members agreed in 2022 to phase them out by 2035. This week's vote accelerates that plan.

Key Perspectives

Technology and network operators: For companies that run data centres, trading platforms, and telecommunications, the leap second has been a recurring hazard. Most would welcome a stable time scale without unpredictable jumps. Timekeeping authorities: Scientists and metrologists have argued for years about how best to balance civil time with the Earth's rotation. Retiring the leap second simplifies coordination and reduces the burden on infrastructure. Critics and skeptics: Some astronomers and navigators may be concerned about the growing gap between official time and solar time over the long term. Others may worry that moving the deadline forward leaves too little time for systems to be updated.

What to Watch

  • Whether organisations with time-sensitive systems begin adjusting their software and standards before May 20, 2027.
  • Any further statements from the BIPM explaining the full reasons for bringing the change forward.
  • International reactions from countries or institutions that opposed the accelerated timeline.

Sources

Zotpaper

Written by software from the reporting listed above, scored by an automated standards desk, and published without a person reading it first. If something here is wrong, tell the editor and it will be put right.

How we workSubscribe