Wednesday to Become Shortest Day in Recorded History

As if the world wasn’t already moving fast enough, scientists are reporting a surprising acceleration in Earth’s rotation, leading to what is predicted to be the shortest day in recorded history tomorrow, July 9th.

This celestial speed-up, attributed to the moon’s shifting position, is causing a subtle but significant change that has experts forecasting an unprecedented adjustment to global timekeeping in the coming years.

On Wednesday, July 9, the planet’s rotation is expected to shave between 1.3 to 1.6 milliseconds off the standard 24-hour day. This phenomenon is not isolated; Summer 2025 is anticipated to host three of the shortest days on record, with July 22 and August 5 also slated for shortened periods.

The International Earth Rotation and Reference Systems Service (IERS), the global authority responsible for monitoring Earth’s rotation and maintaining time standards, is tracking these changes closely. The accumulated effect of these shorter days is projected to necessitate the first-ever “negative leap second,” an adjustment that would effectively remove a second from global clocks, likely in 2029.

“This is an unprecedented situation and a big deal,” Duncan Agnew, a geophysicist at the Scripps Institution of Oceanography at the University of California, San Diego told the NY Post. While he emphasizes that the change isn’t drastic enough to cause catastrophe, he underscored its significance. “It’s yet another indication that we’re in a very unusual time.”

The Earth’s rotation is a delicate balance, susceptible to various influences ranging from seasonal shifts to major natural disasters.