July 22, 2025 is not just another Tuesday—it’s shaping up to be the second shortest day of the year, thanks to Earth’s increasingly quirky rotation.
Earth is set to complete its full spin 1.34 milliseconds faster than the standard 24 hours. You won’t notice it while making your coffee, but atomic clocks definitely will.
⏱️ What’s Going On?
🌀 Earth Is Spinning Faster—Again
- On July 22, Earth’s rotation will finish slightly early—1.34 milliseconds early, to be precise.
- That’s still longer than July 10, which currently holds the record for 2025 at 1.36 milliseconds shorter than 24 hours.
- The shortest day in recorded history? That was July 5, 2024, when Earth zipped through its rotation 1.66 milliseconds faster than normal.
🤯 Why Is Earth Speeding Up?
Scientists are still scratching their heads (and calibrating their atomic clocks), but several theories are on the table:
- Core Shenanigans: Shifts in the flow of Earth’s molten outer core could be redistributing angular momentum, nudging the crust to spin faster.
- Moon Mischief: The Moon’s maximum declination (its position farthest from Earth’s equator) may be tweaking Earth’s axial wobble and affecting rotation.
- Other Factors: Atmospheric pressure shifts, glacier melt, seismic activity, and even human infrastructure can subtly impact rotational speed over time.
🕐 Could a Negative Leap Second Be Coming?
If this rotational acceleration trend continues, scientists might have to do something unprecedented:
🔻 Subtract a second from atomic time.
This so-called “negative leap second” could be needed around 2029, to keep UTC aligned with solar time. It’s never been done before—and it would make your day (literally) shorter.
🛰️ Why It Matters (Even If You Can’t Feel It)
- GPS systems rely on ultra-precise time.
- Satellite communications need perfect sync.
- Financial markets, data centers, and telecom networks all depend on atomic time accuracy.
So while you won’t lose sleep over a missing millisecond, your devices care a lot more than you do.