BALDR Atomic Digital Alarm Clock, Black Automatically Updates: time is synchronized to the radio signal emitted from the U.S. Atomic clock in Colorado, receiving WWVB time. No need to adjust for DST Compact Design: Free standing alarm clock fits on night stands, tables, and shelves Easy to Use: features an alarm with an easy to use snooze function, clock displays time, month, date, day of the week, and indoor temperature in Fahrenheit or Celsius Easy to View: button activated blue backlight is gentle on the eyes while providing maximum illumination. Display remains illuminated for approximately 5 seconds Portable: clock is powered by one AA battery (sold separately), no need for wires or plugs. Measures 3.66x3. 66x3. 66