This year, July 9 will be one of the shortest days due to Earth’s faster rotation. Scientists have been tracking this phenomenon using atomic clocks, which measure tiny variations in the planet’s spin speed.
The length of day (LOD) has increased over the years, resulting in shorter days. In 2020, the shortest LOD was recorded at -1.05 milliseconds. Since then, it has decreased by about half a millisecond each year.
On July 5, 2024, the shortest day occurred with a LOD of -1.66 milliseconds. Earth’s rotation is expected to slow down due to surface changes like polar ice melt and eventually return to its natural state.
The current fast rotation is caused by unknown factors, but researchers expect it to regulate soon. The planet will continue its steady deceleration, which is its natural tendency.
Source: https://eu.northjersey.com/story/news/2025/07/07/earths-rotation-shortens-the-day-on-july-9-what-happens-on-wednesday/84490832007