SCIENCE · VERIFIED DEVELOPMENT
Leap seconds may be phased out as Earth's rotation becomes more predictable
WHY IT MATTERS
The change could impact high-precision computer systems and may lead to the abolition of leap seconds, which have been used to keep timekeeping aligned with Earth's rotation for decades.
What happened
The General Conference on Weights and Measures is considering changing its strategy for adding leap seconds to keep timekeeping aligned with Earth's daily rotation. Leap seconds have been used to account for the Earth's irregular rotation, but the organization may increase the maximum allowed discrepancy between Coordinated Universal Time (UTC) and UT1, the time scale based on Earth's rotation.
This change could be implemented in or before 2035.
The decision is partly driven by the Earth's recent period of unusually rapid rotation, which has reduced the need for leap seconds.
PRIMARY SOURCES
Leap seconds have helped keep clocks synchronized with Earth’s rotation, but their time may be over – here’s why
The Conversation US · Vahe Peroomian, Professor of Physics and Astronomy, USC Dornsife College of Letters, Arts and Sciences · CC BY-ND; link/attribution intake only—no edited republication
CORRECTIONS & UPDATES
- Revision 1 · Initial ingestion · Oct 8, 2026, 12:15 PM
- Revision 2 · Source update detected · Oct 8, 2026, 12:15 PM