Earth's rotation will speed up slightly on three days this summer (July 9th, 22nd, and August 5th), resulting in days shorter by 1.30, 1.38, and 1.51 milliseconds respectively. This minuscule change is due to the moon's position relative to Earth's equator. While imperceptible to humans, these fluctuations are measured using atomic clocks and are influenced by factors like earthquakes and tidal forces. Earth's rotation speed has varied throughout history, gradually increasing the length of a day over millions of years.

Prepared by Olivia Bennett and reviewed by editorial team.