America's official time is kept at a government laboratory in Boulder, Colo., and according to the clock at the entrance, I was seven minutes behind schedule.

Like it or not, it’s time to fall back again. Most of the United States and Canada is about to switch to standard time, moving clocks back an hour Sunday morning. The official time change will ...

A new atomic clock is one of the world’s best timekeepers, researchers say — and after years of development, the “fountain”-style clock is now in use helping keep official U.S. time. Known ...