www.timeanddate.com By Graham Jones and Konstantin Bikos
Earth keeps spinning faster—but why? timeanddate checks the latest numbers.
Shortest Day of Atomic-Clock Era
Earth has recorded its shortest day since scientists began using atomic clocks to measure its rotational speed.
On June 29, 2022, Earth completed one spin in 1.59 milliseconds less than 24 hours. This is the latest in a series of speed records for Earth since 2020.
Earth’s Fluctuating Spin
Earth spins once every 24 hours with respect to the Sun—this is why the Sun appears to rise and set every day.
In general, over long periods, Earth’s spin is slowing. Every century, Earth takes a couple of milliseconds or so longer to complete one rotation (where 1 millisecond equals 0.001 seconds).
Within this general pattern, however, the speed of Earth’s spin fluctuates. From one day to the next, the time Earth takes to complete one rotation goes up or down by a fraction of a millisecond…
