Thanks to thousands of years’ worth of observations recorded by astronomers, we know that the Earth’s rotation has slowed down over the years!
The rotation – or the length of a day – can vary by as much as a millionth of a second. It hasn’t been a steady decline, but over that period of time the decline has been up to 25 millionths of a second per year.
This is all due to the way that the moon interacts with the tidal bulges on our planet, but there’s also a relationship between the weather and the Earth’s rotation.
Don’t worry too much though, at this rate it’ll still be spinning for another 5 billion years!