Get the latest updates as we post them — right on your browser

. Last Updated: 07/27/2016

Second-Guessing Time

PARIS -- Get ready to reset your watches: A leap second is coming.

"The Earth has been turning too slowly,'' explained Martine Feissel, director of the grandly named International Earth Rotation Service, the organization that decides every six months whether the world needs to add or subtract a second.

The leap second, the 21st ordered by the body since 1972, will occur at midnight Monday -- briefly delaying the onset of Tuesday.

The change will affect everything that is synchronized by satellites -- from communication, navigation and air traffic control systems to the computers that link global financial markets.