Why July 9 might have been the shortest day ever in history

Scientists around the world are puzzled as the Earth’s rotation continues to behave in unusual ways. On July 9, 2025, the planet may have experienced its shortest day ever.

According to The New York Post, this might be the shortest day ever recorded in history, with the Earth’s rotation expected to be around 1.3 to 1.6 milliseconds faster than the usual 24 hours.

The change is so small that most people wouldn’t even notice it, but it’s significant enough for scientists who closely monitor the length of each day.

The measurements are made in milliseconds, and experts believe that July 9 could have beaten the previous record set on July 5, 2024, when the Earth rotation made the day 1.66 milliseconds shorter than normal.

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The reason behind this surprising change in Earth rotation is still unclear. Normally, the Earth spins slightly faster when the Moon is far north or south of the equator, but this alone doesn’t fully explain the current speed-up.

Earthquakes and shifts in the atmosphere or oceans can affect rotation slightly, but scientists say those factors don’t seem to be responsible this time.

Instead, many experts now believe the cause of the faster Earth rotation might be coming from deep inside the Earth itself.

So far, no model has fully explained the leap in speed, making this a mystery in the scientific world.

Other potential shortest days might fall on July 22 or August 5, depending on the Moon’s position. What was once science fiction is becoming a scientific reality, with Earth rotation now changing more than ever before in recent years.

Since 2020, Earth rotation has led to new shortest days being recorded nearly every year, showing a strange but consistent trend.

As the Earth continues to rotate at these slightly faster speeds, researchers are watching closely and wondering what it means for the planet’s long-term rhythms.