Clock Lord

The radio clock, often referenced as the atomic clock, is one of the most accurate clocks on the planet.   These clocks are referred to as atomic clocks because their time is based on radio waves intercepted from actual atomic clocks, and if synchronized correctly, are accurate to the second.  Once each day, (usually during the nighttime) a radio clock will attempt to receive a signal broadcast from an atomic clock, and adjust its time accordingly.  As atomic clocks are accurate down to miniscule fractions of a second, for casual use, the radio clock is much more accurate than most timepieces. 

There are several longwave radio transmitters around the world that broadcast an atomic clock signal, in the US, WWVB, a true atomic clock, is located in Fort Collins, Colorado and broadcasts a signal receivable throughout North America.