Digital Radio Atomic Wall Clock displays month, date, day of the week, and time (hours, minutes, and seconds) in a.m./p.m. or 24-hour time. Also displays ambient temperature and relative humidity. LCD features digits 2-¼" high for visibility from up to 20 feet away. Clock is accurate to 1/10,000 of a second and relative humidity has a 1% resolution. Controlling radio signal from NIST in Boulder, Colorado automatically adjusts clock to precise time, daylight savings, leap year, and leap seconds.