Graham Jones, a science communicator at the company, told Newsweek that the past year has been approximately 65 milliseconds shorter than average—”the new shortest year on record.”

It’s all because of Earth’s rotational speed. A small shift in how fast the planet spins might cause a day to be a tiny fraction of a second longer or shorter than its 86,400-second average.

“If you look at the length of a day, throughout the year, you can kind of see peaks and troughs,” Graham said. “And one of the key things that affects that is the moon’s orbit and the moon’s distance from the Earth.”