Earth's Spin Is Speeding Up, Making Your Days Shorter: Report

Earth is expected to spin faster than usual in the upcoming weeks, leading to slightly shorter days, scientists report, according to Live Science. On July 9, July 22, and August 5, 2025, the position of the moon will influence Earth's rotation, making each day between 1.3 and 1.51 milliseconds shorter than the standard 24 hours.

Normally, a full day on Earth lasts about 86,400 seconds, or 24 hours. But Earth's rotation is not constant; it is affected by several factors, including the gravitational pull of the moon and sun, the planet's magnetic field, and shifts in Earth's mass due to natural or human activity, according to the science news portal.

Historically, Earth's rotation has been gradually slowing down. About 1 to 2 billion years ago, a day lasted only 19 hours, mainly because the moon was much closer to Earth and had a stronger gravitational effect. Over time, as the moon moved away, our days got longer.

Interestingly, in 2020, scientists recorded Earth spinning faster than at any point since the 1970s. The shortest-ever recorded day occurred on July 5, 2024, which was 1.66 milliseconds shorter than usual.

The moon's distance from Earth's equator on certain days can speed up the planet's spin, similar to how a spinning top moves faster when its axis changes. Climate-related changes, such as the melting of ice and groundwater movement, have also contributed to shifts in Earth's rotation. Even earthquakes and seasonal changes can slightly affect the length of our days.

Single events can also affect Earth's spin: the 2011 earthquake that struck Japan shortened the length of the day by 1.8 microseconds. Even the changing seasons affect Earth's spin, Richard Holme, a geophysicist at the University of Liverpool, told Live Science via email.

"There is more land in the northern hemisphere than the south," Holme said. "In northern summer, the trees get leaves, which means that mass is moved from the ground to above the ground, further away from the Earth's spin axis."

The rate of rotation of any moving body is affected by its distribution of mass. When an ice skater spins on the spot, they rotate faster when their arms are tight to their chest, and slow themselves down by stretching their arms out. As Earth's mass moves away from its core in summer, its rate of rotation must decrease, so the length of the day increases, Holme explained.