July 9 was unusually short thanks to changes in how fast the Earth is spinning. But two other days this summer are expected to be even shorter.

The August full moon, known as the sturgeon moon, will be visible on Aug. 9, 2025. Winter solstice 2025, which marks the start of winter in the Northern Hemisphere, will occur on Sunday, Dec. 21, 2025 ...

As Earth spins faster than it has in decades, atomic clocks are catching the difference, and shorter days are on the horizon.