Wake up and see the time displayed on your wall or ceiling. Projection brightness is adjustable. Adjustable snooze alarm, US time zone map, perpetual calendar, 12/24 hour time display, monitors indoor temperature in Fahrenheit or Celsius, automatically updates for Daylight Saving Time, AC power adaptor included. Also runs on two AA batteries, not included. When operating on AC, the Projection Alarm Clock can project time constantly, and when operating on batteries, it will project time for three seconds when a button is pressed.