Scientists anticipate that Earth's rotation will quicken enough to create three shorter days between July and August, starting Wednesday, July 9.

Thanks to atomic clocks (and all the worldly forces that influence them), scientists know that Earth's rotation has begun to slow down, thanks in large part to the loss of ice coverage in polar regions.

Earth is set to experience unusually short days in July and August 2025. The Moon's orbital position is subtly accelerating Earth's rotation. These days will be milliseconds shorter, impacting precision systems.