Oversized digital atomic clock makes for a perfect timepiece in lobby, living room or conference center. With radio-controlled technology, this clock self-sets to your time zone setting automatically. This clock self-adjusts during Daylight saving time changing twice a year to keep the time accurate. Clock receives WWVB radio frequency from NIST station, located in Fort Collins, CO, synchronizing and keeping accurate to ten billionths of a second per day. Select your time zone and then press/release Search button to manually search for Atomic signal. Place clock in the direction of the Colorado overnight to receive best transmission. Clock will continue to search until Tower icon stops flashing and remains solid. If clock is out of 2,000 mile radius from the radio tower, it can be manually set, and can turn of Atomic signal search. This sophisticated timepiece features adjustable view for calendar date/day with weekday. Requires 6 AA batteries for operation and versatile to mount onto wall or stand onto countertop. Add-on bonus feature, by purchasing separate (TX141TH-BV3) wireless remote sensor to detect temperature and humidity, so you can monitor the outdoors as well.