The Earth's rotation is accelerating and today a historic event that affects our days could occur.

A day is 24 hours, or 86,400 seconds, which is the time it takes for our planet Earth to rotate on its axis with an accuracy of approximately one millisecond.

However, since 2020, this process has begun to accelerate, imperceptibly shortening the 24-hour standard solar day by a few milliseconds. A millisecond (ms) is equivalent to 0.001 seconds, significantly less than the blink of an eye, which lasts about 100 milliseconds.

The only way to measure these tiny daily variations in the Earth's spin rate is with atomic clocks , which were introduced in the 1950s. The number of milliseconds above or below 86,400 seconds is known as the length of day (LOD).

And on this website, you can see exactly how long each day lasted. For example, Thursday, June 26th, lasted 23 hours, 59 minutes, 59.9988409 seconds, and this Friday, June 27th, is expected to last 23 hours, 59 minutes, 59.9989855 seconds.

As astrophysicist Graham Jones points out for the website Time and Date, " Our planet is a near-perfect chronometer , but not quite." And as the planet has been accelerating for several years, this will have direct consequences for the length of days, and by 2025, Earth is close to achieving a new record for shortest days.

Specifically, July 9, July 22, and August 5 have the potential to become the shortest day in history due to the Moon's orbit, as the Earth's rotation is actually faster when the Moon is much farther north or south of Earth's equator.

What's not clear is why this happened. "Long-term variations in the Earth's rotational speed are influenced by a long list of factors, including the complex motion of the Earth's core, oceans, and atmosphere," Jones explains. And other factors, like the one we told you about last week, with the massive dam China built.