The Eastern Standard Time zone includes the states on the eastern side of the United States. Twenty-three states plus Washington, D.C., make up this time, which stretches from Maine to Florida and as far west as Michigan and Indiana. While 17 states and Washington are fully within the Eastern time zone, six states are split between the Eastern and Central time zones. These states are Florida, Alabama, Indiana, Michigan, Kentucky and Tennessee. This time zone is behind Greenwich Mean Time by five hours.
The Central Standard Time zone includes most of the states in the center section of the country. Twenty-one states make up the Central time zone, though only nine are fully within its borders. Five states -- Kansas, Nebraska, North and South Dakota, and Texas -- are partly in Mountain time. Six other states are partly within the Eastern time zone. Central Standard Time is six hours behind Greenwich Mean Time.
Mountain Standard Time includes the western half of the central states. Fourteen states observe Mountain Standard Time either exclusively or partially. For example, only Sherman, Wallace, Greeley and Hamilton counties in Kansas are in this time zone while the rest of the state is in the Central time zone. Other states that are only partly within Mountain time are Idaho, Oregon, North and South Dakota, Nebraska, Texas and Nevada. Mountain Standard Time is seven hours behind Greenwich Mean Time.
The Pacific Time Zone is made up of the states closest to the Pacific Ocean. Only five states make up this time zone. States are California, Washington, Oregon, Nevada and the northern half of Idaho. When the rest of the country is observing daylight-saving time, Arizona reverts to Pacific Standard Time instead of its usual Mountain Standard Time. The whole state observes time this way except for the Navajo Indian Reservation.