Traceable® Digital Clock has 2-1/4 inch-high big digits for visibility from 20 feet. Accuracy is 1/10,000 of a second. Radio signal from NIST in Colorado automatically adjusts clock to precise time, daylight savings, leap year, and leap seconds (earth rotation wobble corrections). Display shows AM/PM or 24-hour time, month, date, day-of-the-week, and ambient temperature (32 to 122 °F and 0 to 50°C with 0.1° resolution). Large digits are 2-1/4 inches high for viewing from 20 feet.