There are Nine standard time zones in the United States.
These time zones cover the contiguous United States, the states of Alaska and Hawaii, and the overseas territories. The nine-time zones are:
Pacific Standard Time (PST)
Mountain Standard Time (MST)
Chamorro Standard Time (UTC+10)
Atlantic Standard Time (AST)
Central Standard Time (CST)
Alaskan Standard Time (AKST)
Eastern Standard Time (EST)
Hawaii-Aleutian Standard Time (HST)
Samoa standard time (UTC-11)
Time Zones in the contiguous United States
Of these nine-time zones, four are in the contiguous United States, which comprises the 48 adjoining states. The Mountain Standard Time Zone is prevalent in the states that are a part of the Rocky Mountains. The states in this time zone are Colorado, New Mexico, Utah, Arizona, Montana, Wyoming, Texas, North Dakota, South Dakota, Nebraska, Idaho, Kansas.
The Eastern standard time zone roughly includes the states that are located on the Atlantic Coast. The states in the eastern two third part of the Ohio Valley are also included in this time zone. Apart from the federal district of Washington D.C, the states included in this time zone are New York, Virginia, West Virginia, Florida, Maryland, Maine, Rhode Island, South Carolina, Connecticut, Delaware, Georgia, Indiana, Kentucky, Massachusetts, Michigan, New Hampshire, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, and Vermont.
The states that are on the Pacific coast, along with Nevada and Idaho panhandle, come within the Pacific standard time zone. There are five states within this zone and these are Oregon, California, Idaho, Nevada, and Washington.
The Central standard time zone roughly includes the Mississippi Valley, the Gulf Coast, and the Great Plains. States which come under this time zone are North Dakota, South Dakota, Wisconsin, Texas, Kansas, Florida, Michigan, Arkansas, Oklahoma, Iowa, Nebraska, Alabama, Illinois, Indiana, Kentucky, Louisiana, Minnesota, Mississippi, Missouri, and Tennessee.
Alaska and Hawaii
Alaska and Hawaii, which are not a part of the contiguous United States have their own time zones. Most of the state of Alaska follows the Alaska standard time zone. The Hawaii-Aleutian standard time zone comprises the state of Hawaii and a major part of the Aleutian Islands chain.
For the overseas territories, three different time zones are used. The Chamorro standard time zone includes the Northern Mariana Islands and Guam. Puerto Rico and the US Virgin Islands are a part of the Atlantic Standard time zone, while American Samoa comes within the Samoa standard time zone.