Overview

• July 9 saw Earth complete its rotation 1.3 milliseconds faster than usual, setting a new shortest day record.
• Additional abbreviated rotations are predicted on July 22 (1.38 ms) followed by August 5 (1.50 ms) as the Moon reaches its farthest point from Earth’s equator.
• The International Earth Rotation and Reference Systems Service alongside global timekeepers are tracking variations with atomic clocks to maintain UTC precision.
• The acceleration trend, ongoing since 2020, remains unexplained by oceanic or atmospheric models, pointing to possible deep-Earth processes.
• If the spin-up continues, timekeepers anticipate the need for the first negative leap second in 2029 to realign atomic time with solar time.