Brace for shorter days soon: Earth is rotating faster than ever recorded

In an unexpected twist, Earth's spin is set to accelerate in July and August, leading to the shortest days on record - with July 9, July 22 and August 5 tipped to lose precious milliseconds

Brace for a time crunch — Earth is picking up speed. In the coming weeks, our planet will spin faster than usual, causing a few days in July and August to be slightly shorter than 24 hours. Scientists have pinpointed July 9, July 22 and August 5 as the fastest-spinning days of 2025, according to data from timeanddate.com.

 

You won’t notice the change without precision instruments, but it's happening: on August 5, Earth is expected to complete its rotation 1.51 milliseconds quicker than the standard 86,400-second day — a blink of time, but a real shift in planetary motion.

Why is the Earth suddenly spinning faster?

A day on Earth is defined by the time it takes to complete one full spin on its axis — about 24 hours. But this rotation is far from constant. It’s shaped by a complex interplay of factors, including the gravitational tug of the sun and moon, Earth’s shifting magnetic field, and even changes in mass distribution caused by melting ice, rising seas, and earthquakes.

 

For most of Earth’s history, the planet’s spin has been slowing down, lengthening our days. Around 1 to 2 billion years ago, a day lasted just 19 hours, thanks to the moon’s stronger pull when it orbited closer to Earth.

 

But recently, that slowdown has reversed. Scientists say we’ve entered a period of erratic rotational behaviour, with 2020 marking the beginning of an acceleration phase. That year, Earth began spinning faster than at any point since atomic clock records began in the 1970s. The all-time record came on July 5, 2024, when Earth completed a full spin 1.66 milliseconds faster than usual.

It all comes down to the Moon — and its strange position this summer

The acceleration this July and August may be partly driven by the moon’s shifting position. On July 9, July 22, and August 5, the moon will be at its furthest distance from Earth’s equator, altering the nature of its gravitational influence. Imagine Earth as a spinning top. If you push it from the middle, it rotates differently than if you spin it from the top and bottom. A similar mechanism is at play here: when the moon’s gravitational pull moves closer to Earth’s poles, it boosts the spin rate, slicing off tiny fractions of time from each day.

Humans may be tipping the balance, too 

While natural forces dominate Earth’s spin, human activity is now entering the equation. NASA researchers have shown that between 2000 and 2018, changes in groundwater levels and melting ice — linked to climate change — increased the planet’s day length by about 1.33 milliseconds per century. Even isolated events can make a difference. The devastating 2011 earthquake in Japan was so powerful it shortened the day by 1.8 microseconds. According to geophysicist Richard Holme, seasonal shifts also nudge Earth’s rotation in subtle ways.

A ticking consequence: timekeeping may soon change 

If Earth’s rotational speed continues to rise, it could prompt an unprecedented change in global timekeeping. For the first time in history, scientists may have to subtract a leap second — likely in 2029 — to keep atomic clocks aligned with the planet’s actual rotation.