Tue Feb 25 08:50:47 UTC 2025: ## Earth’s Rotation Slowing, But Gregorian Calendar Holds Up
**CHENNAI, INDIA (February 25, 2025)** – A recent article in The Hindu explores the ongoing evolution of timekeeping, highlighting the accuracy and persistent relevance of the Gregorian calendar. The piece explains that the Gregorian calendar, implemented in 1582 by Pope Gregory XIII, addresses the inaccuracies inherent in previous systems by specifying that century years are only leap years if divisible by 400. This corrects for the slight overestimation of a tropical year (the time Earth takes to orbit the sun) by the Julian calendar’s leap year system.
While the Gregorian calendar remains remarkably accurate, the article notes that highly precise atomic clocks have detected a minuscule slowing of Earth’s rotation due to the moon’s gravitational pull, approximately 0.06 microseconds per year. This subtle change affects the precise calculation of equinoxes, but the current calendar system continues to function effectively despite this. The article serves as a reminder of the ongoing efforts to refine our understanding and measurement of time.
First Piper 