Moscow: In a phenomenon that has puzzled scientists across the globe, Earth’s rotation is mysteriously speeding up and today, August 5, 2025, is expected to become one of the shortest solar days ever recorded. The day will be 1.25 milliseconds shorter than the standard 24-hour day, a difference far too small for humans to notice, yet significant enough to raise alarm among scientists and timekeepers.
The discovery was highlighted in a report by Timeanddate.com, which tracks Earth’s rotation with high precision. The platform noted that August 5 would join July 9 and July 22 as one of three days in 2025 where Earth's solar day the time it takes for the sun to return to the same position in the sky dips below the traditional 86,400 seconds. The shortest day ever recorded so far was on July 5, 2024, when the Earth completed a rotation 1.66 milliseconds faster than average.
To understand why this is important, it's essential to define what constitutes a day. A solar day, which is how we measure time in daily life, spans from one noon to the next and is based on Earth’s rotation relative to the sun. However, Earth’s actual rotational period called a sidereal day is slightly shorter, lasting about 23 hours, 56 minutes, and 4.1 seconds. This discrepancy is due to Earth’s simultaneous revolution around the sun.
Historically, Earth's rotation has been slowing down. Tidal friction caused by the gravitational pull of the Moon has gradually transferred Earth’s rotational energy, lengthening days by fractions of a second over centuries. That trend seemed stable until recently.
Since around 2020, researchers have noticed a counterintuitive trend: the Earth is spinning slightly faster, and no single cause has been definitively identified. Some scientists have hypothesized that changes in the flow of Earth’s molten core might be affecting its angular momentum. Others suggest that melting polar ice, changes in atmospheric pressure, and even ocean currents could be redistributing Earth’s mass in ways that impact its spin.
Particularly intriguing is the role of the Moon in these variations. On the three shortest days predicted for 2025 July 9, July 22, and August 5 the Moon is positioned at a high declination relative to Earth’s equator. This subtle shift may be affecting the gravitational forces acting on our planet, influencing tidal motion and, consequently, rotation speed.
Despite intense speculation, no single theory has fully explained the recent acceleration. “Most scientists believe it is something happening deep inside the Earth,” said Leonid Zotov, an Earth rotation expert at Moscow State University. “Ocean and atmospheric models don’t explain this huge acceleration.”
If this trend continues, the implications for timekeeping could be profound. Atomic clocks, which provide the standard for Coordinated Universal Time (UTC), may eventually require a negative leap second to maintain synchrony with Earth's actual rotation. This would mark the first time in history that a second would be subtracted from official time, rather than added.
However, such a move could present major challenges. Digital systems across the globe including GPS, financial trading platforms, and computer networks rely on consistent and predictable time. A negative leap second could disrupt these systems, requiring complex updates to software and hardware infrastructures.
While the average person won’t feel the effect of a few milliseconds being shaved off a day, the Earth’s subtle shift in rhythm is a signal of deeper planetary processes at work. Scientists continue to monitor these developments, not just to adjust our clocks, but to better understand the planet we live on and how it continues to change in unexpected ways.