The planet’s rotation fluctuates as it travels around the sun, and measurements suggest we’re losing more than a millisecond during the long days of summer.

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.

Earth just recorded one of its shortest days on record on Wednesday, and scientists say its accelerating rotation is expected to shorten two more days this summer. On July 22 and August 5, Earth's spin is projected to speed up,