The unit works on receiving the time radio signal. The time signal is generated by the US Atomic Clock which is located in Colorado. (The Atomic Clock is operated by the US Department of Commerce's National Institute of Standards and Technology.) To enhance good reception, avoid placing the unit near television sets, metal surfaces, computers or electric devices as these devices will interfere with the reception of radio signal.

FEATURES: Atomic clock functlon with automatic daylight saving time / standard time adjustment. Solar power for full operation. No external battery needed. Jumbo display with maximum digit height 47mm. Display time with running second / calendar with month, date and day-of-week. Digital map showing the current time zone selected, for easy recognition. 12/24HR display format user selectable. POWER SAVE mechanism for minimal power consumption in dark. Hang on wall or stand on the desktop (with built-in easel stand). Display Size: 2-1/4". Clock is 10" in diameter.

Please note: The atomic function will not operate in Hawaii or Alaska. This item cannot communicate with the National Institute of Standards and Technology from either Hawaii or Alaska and therefore must always be set manually while in those states.