Features: Atomic time with manual setting. Automatically sets to exact time. Accurate to the second. Automatically updates for daylight saving time (on/off option). 4 time zone settings. Simple operation: insert 1 "AA" alkaline battery. Specifications: Simple Operation: Insert One AA Alkaline Battery. After signal is received, press Time Zone button to set. Four Time Zone Settings. Daylight Saving Time Option On/Off. Manual Reset Button. * Power requirements: Clock: One AA Alkaline Battery.