This is my take on an Arduino based clock that syncronizes to NIST's atomic time signal WWVB.
Universal Solder's ES100-mod is used to recieve and decode the phase-modulated broadcast from Fort Collins, Colorado.
Time data is being displayed on a traditional clock-style quad 7-segment display. I am using an i2c controlled flavor from Adafruit.
Every hour the reciever module is asked for an update. That's sometimes tough here on the east coast, so It will keep trying until it's successful. The system keeps track of the recieved UTC time and applys timezone / daylight savings time offsets as appropriate. Local time is shown on the display. If it's been over 6 hours, additional LEDs will blink to let us know.
Released under the MIT license, see LICENSE