Earth is speeding up and our days are getting shorter (literally).

Since 2020, scientists have been tracking a surprising trend: Earth is spinning just a little bit faster.

According to the International Earth Rotation and Reference Systems Service (IERS), based in Washington, D.C., our planet’s rotation has been accelerating slightly. The result? Days are becoming shorter by a few milliseconds a tiny difference, but one that’s measurable with today’s precision instruments.

Historically, Earth’s spin has been gradually slowing due to the gravitational pull of the Moon. So this recent reversal of pace has caught scientists off guard. Several potential causes have been proposed shifts in Earth’s molten core, glacial melt redistributing mass, and even atmospheric changes linked to climate patterns like El Niño and La Niña.

While these differences don’t affect daily life (you won’t notice a 1.5-millisecond change), they do matter for high-precision technologies like GPS, satellite communications, and atomic clocks. If the trend continues, we might even need to adjust global timekeeping potentially by subtracting a leap second for the first time ever.

It's a reminder that even something as constant as the length of a day isn’t set in stone. The Earth is always changing and sometimes, it’s in ways we can barely feel, but must carefully track.

A rare cosmic phenomenon is causing Earth to spin faster than usual so much so that scientists are expecting record-breaking rotation speeds on July 22 and August 5, 2025. These won’t be the shortest days in terms of daylight, but in actual time Earth will complete its full spin a few milliseconds faster than the standard 24 hours. While it may sound minor, this subtle speed-up is significant for systems that rely on ultra-precise timekeeping.

This acceleration in Earth’s rotation is driven by complex and interconnected natural forces. Shifts in the planet’s molten core, glacial melting, seismic activity, and even tidal interactions with the Moon can change how Earth balances and moves through space. Over time, these tiny adjustments can add up, leading to measurable impacts on the length of a day. Though we can’t physically feel this speed-up, it’s enough to cause ripples in how we measure time itself.

Why does this matter? Our atomic clocks, GPS systems, and internet servers depend on Earth’s consistent rotation to stay accurate. If this trend continues, scientists may be forced to introduce a “negative leap second” a rare correction that subtracts time instead of adding it. It’s a reminder that even the most reliable cycles on our planet are still part of a dynamic, shifting system governed by forces beyond our everyday perception.

Source: International Earth Rotation Service (IERS), Nature Geoscience, 2025