The nine time zones used across the United States and its territories. The most populous US time zone: the entire East Coast from Maine to Florida, plus Michigan, Indiana (mostly), and Kentucky's eastern half. The Midwest and much of the South and central Plains, from Chicago and Dallas to New Orleans and Minneapolis, plus the Florida panhandle and El Paso's Texas neighbors further east. The Rocky Mountain states — Colorado, Utah, Wyoming, Montana, and parts of Idaho, New Mexico, and Texas — plus Arizona, which uniquely stays on standard time year-round. The West Coast — California, Oregon, Washington, and Nevada — plus most of Idaho's northern panhandle. All of Alaska except the far western Aleutian Islands, which sit in the Hawaii-Aleutian zone. Hawaii (no DST, permanent HST) and the far-western Aleutian Islands of Alaska (which do observe DST as HDT).

Puerto Rico and the US Virgin Islands. American Samoa. Guam and the Northern Mariana Islands. Looking for a coast instead of a formal zone name? Here's what time zone each US coastline runs on. California, Oregon, and Washington are the three West Coast states, all on Pacific Time year-round. Fourteen states plus Washington, D.C. line the Atlantic coast, nearly all entirely on Eastern Time except Florida's panhandle. Texas, Louisiana, Mississippi, and Alabama are on Central Time; Florida's Gulf coast splits between Central (panhandle) and Eastern (peninsula).