Earth is spinning faster this summer, making the days marginally shorter and attracting the attention of scientists and timekeepers. But these days are not ‘short’ in terms of how many sunlight hours they have — rather because they clock in at slightly less than exactly 24 hours.

Zotov predicts Earth’s rotation may soon decelerate once again. If he’s right, this sudden speeding-up could prove to be just a temporary anomaly in the planet’s long-term trend toward slower rotation and longer days.

Tuesday, July 22, is expected to be the second of three days in 2025 where more than a millisecond could be shaved off the day due to Earth's rotation