All,

  The National Institute of Standards and Testing (NIST) WWVB radio station has turned 50.  This station supplies the 60 KHz calibration signal to your atomic wall clocks and watches plus other things that will pick up that signal as with some of the indoor/outdoor thermometers with clocks.  The information within this signal updates your atomic timepiece automatically to your local time.  There were expensive timepieces available in the 1960's, 70's, 80's that picked up this time signal.  The signal had changed to a new protocol and those older clocks are now obsolete.  This is not to be confused with the WWV/WWVH signals at 2.5, 5, 10, 15, and 20 MHz that are receivable with most shortwave radios.  Amateur radio operators (Hams) still use these frequencies to calibrate their rigs.  I also use those frequencies to calibrate my homemade frequency counter. 

  Story: http://www.nist.gov/pml/div688/wwvb-062513.cfm

  WWVB: http://www.nist.gov/pml/div688/grp40/wwvb.cfm

  WWV: http://www.nist.gov/pml/div688/grp40/wwv.cfm

  Joelene

The atomic clock brought a new aspect of time ... the "leap second"