https://www.mercurynews.com/2022/08/09/june-29-was-the-shortest-day-ever-recorded-heres-how-that-happened/ > (CNN) — June 29 was the shortest day on Earth since the invention of the atomic clock. > The planet’s rotation measured in at 1.59 milliseconds short of the normal 24 hours, according to the International Earth Rotation and Reference Systems Service, an organization in charge of global timekeeping.