Earth’s Rotation Speeds Up: Days Shorten in July and August

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Scientists have observed a curious astronomical event in the summer of 2025: Earth’s rotation has slightly accelerated, making days a few milliseconds shorter than normal. On July 9 and again on July 22 and 23, the planet completed its rotation roughly 1.4 milliseconds faster than the standard 86,400 seconds.

Though imperceptible to humans, the change holds significance for scientists, GPS operators, and high-frequency data networks that rely on precise timekeeping. If this trend continues, global time authorities may soon have to consider implementing a “negative leap second”—a move never before taken in history.