Seth thomas® 14 Diameter radio-controlled time standard wall clock 14" Diameter Radio-Controlled Time Standard Wall Clock, Black Case Superb accuracy--automatically adjusts its time to match the National Bureau of Standards Atomic Clock in Boulder, Colorado. Clock automatically sets itself for daylight- savings time changes, saving you time. Features a cesium atomic clock (WWVB) signal from the National Institute of Standards. Absolute accuracy at all times—within one second over one million years! Radio controlled anywhere in the contiguous U.S, meaning you can travel and still know what time it is!