Three radio stations in the United States mainly broadcast one thing: the official time. The three are radio stations WWV and WWVB, in the state of Colorado, and WWVH, on the island of Kauai in Hawaii. They send out signals that are used by millions of clocks and other time-keeping instruments around the country. The federal government launched the service shortly after World War II. WWV, WWVB and WWVH are part of the U.S. National Institute of Standards and Technology, or NIST. Don Sullivan headed the timekeeping stations for NIST from 1994 to 2005. He warned that, “If you shut down these stations, you turn off all those clocks.” Yet the administration of President Donald Trump has offered a plan to close them down.