Shortest Day on Record?

If you’re thinking that you didn’t accomplish much yesterday, August 5, 2025, it might be because the day was shorter than usual. I don’t mean that the daylight hours were shorter. Earth’s solar day was shorter than the typical 24 hours, which equals 86,400 seconds. You probably didn’t notice because the day was only 1.25 milliseconds shorter. Blaming the shortest day won’t help—you’ll need to find some other reason for not achieving more.

Earth’s rotation speed had been gradually slowing down, but for some reason it started speeding up in recent years, making the days shorter. Official and precise records of solar day lengths since 1973 show that they were getting longer. Earth’s gravity creates friction against the Moon, causing it to drift farther away and slowing Earth’s rotation. A slower rotation results in longer days.

The Moon’s position relative to Earth’s equator creates tidal forces that very subtly influence Earth’s rotation rate. Scientists speculate that the slower rotation of Earth’s liquid core might cause the outer layers of the planet to spin faster, but that remains only speculation.

We can’t really say that yesterday was the shortest day because July 5, 2024, was 1.66 milliseconds shorter than the usual 24 hours. Don’t worry about any noticeable change in the length of days. God has given us an incredibly stable planet on which to live. Many finely tuned factors make life on Earth and our existence possible, and it could not have been accidental. This remarkable planet is further evidence that God exists.

— Roland Earnst © 2025

Reference: space.com