NEW YORK, July 21: Earth will complete its rotation slightly faster than usual on Tuesday, July 22, resulting in one of the shortest days ever recorded. The planet’s day will be 1.34 milliseconds shorter than the standard 24 hours — a difference too small to notice but significant in tracking Earth’s rotational trends.

Since 1973, when atomic clocks began recording Earth's rotation precisely, the shortest day was 1.05 milliseconds less than 24 hours, recorded before 2020. However, since 2020, Earth has repeatedly set new speed records, with the shortest day so far occurring on July 5, 2024, at 1.66 milliseconds less. In 2025, July 10 currently holds the shortest day with 1.36 milliseconds less, followed closely by the upcoming July 22 at 1.34 milliseconds.

This recent acceleration contradicts the long-term trend of Earth’s rotation slowing down over millions of years, primarily due to tidal friction caused by the Moon. Historically, days have lengthened as the Moon’s gravitational pull saps Earth’s rotational energy.

Scientists remain uncertain about the cause of the current speeding up. Some suggest changes deep within Earth’s liquid core may be redistributing momentum, causing the crust and mantle to spin faster. Other theories point to melting polar ice and rising sea levels but see these as more likely to moderate rather than drive the acceleration.

Leonid Zotov, an expert in Earth rotation at Moscow State University, told Timeanddate.com that atmospheric and ocean models do not explain the acceleration, suggesting it originates from internal Earth processes. He also predicts that Earth’s rotation may soon slow down again, indicating this spike in speed could be temporary.

If this trend continues, it may necessitate the introduction of a “negative leap second” — a removal of one second from atomic clocks — as early as 2029, an adjustment never before implemented.

Summary: Earth is spinning faster than usual, creating some of the shortest days on record. While the exact cause remains unclear, the phenomenon challenges long-standing patterns of Earth’s rotational slowdown. Scientists continue to monitor the situation closely.