Which States Are Split Into Two Time Zones?

Get the Answer to a Popular U.S. Geography Trivia Question

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There are 24 time zones in the world and six of those cover the 50 states that make up the United States. Within those time zones, 13 states are divided into two zones.

Quite often, just a small portion of these states are in a different time zone than the rest of the state. But South Dakota, Kentucky, and Tennessee are nearly cut in half by the time zone change. This is not unusual, as time zones throughout the world zig and zag along lines of longitude with no distinct pattern. But why are time zones like this, and how exactly is the United States split?

Why Are the Time Zones So Crooked?

Time zones are crooked because it is up to each government to regulate them in their country. There are standard time zones for the world, but where exactly those lie and whether to split the country up according to these is a decision made by individual nations.

The United States, for example, had its time zones standardized by Congress. When first drawing the lines, officials tried to avoid splitting metropolitan areas and took other factors into account that might have complicated life for each area's residents. In many places, U.S. time zone lines do actually follow state borders, but that is certainly not always the case, as you will see in the following 13 states.

2 States Split by Pacific and Mountain Time

The majority of western states are in the Pacific time zone. Idaho and Oregon are the two states with small portions following Mountain time. 

  • Idaho: The entire lower half of Idaho is in the Mountain time zone and only the northern tip of the state uses Pacific time.
  • Oregon: Almost all of Oregon is on Pacific time, and only a small area of the east-central border of the state observes Mountain time.

5 States Split by Mountain and Central Time

From Arizona and New Mexico to Montana, the southwestern and Rocky Mountain states mostly use Mountain time. However, this time zone peaks over the borders of a few states, leaving five states with a Central-Mountain time split.

  • Kansas: A small chunk of the far western border of Kansas uses Mountain time, but the majority of the state is on Central time.
  • Nebraska: The western portion of Nebraska is on Mountain time but most of the state's population uses Central time. The cities of Valentine, North Platte, and the capital of Lincoln, for example, are all in the Central time zone.
  • North Dakota: The southwestern corner of North Dakota is on Mountain time but the rest of the state uses Central.
  • South Dakota: This state is almost cut in half by the two time zones. All of eastern South Dakota is on Central time, while the majority of the western half—which includes Rapid City and the Black Hills mountain range—follow Mountain time.
  • Texas: The extreme western corner of Texas that borders New Mexico and Mexico is on Mountain time. This includes the city of El Paso. The rest of the state, including the entire panhandle, is on Central.

5 States Split by Central and Eastern Time

On the other side of the central United States is another time zone line that splits five states between the Central and Eastern time zones.

  • Florida: The majority of Florida's panhandle, including the city of Pensacola, is on Central time. The rest of the state is in the Eastern time zone.
  • Indiana: This state has two small pockets of Central time on the western side. In the north, Gary is on Central time because of its proximity to Chicago, while South Bend is on Eastern time. In the southwest, a slightly larger section of Indiana is in the Central zone.
  • Kentucky: Kentucky is cut almost in half by time zones. The western part of the state, including Bowling Green, is on Central while the eastern half, including Louisville and Lexington, is on Eastern time.
  • Michigan: The division between Central and Eastern time zones runs through the middle of Lake Michigan and curves west through Michigan's Upper Peninsula. While the entire Lower Peninsula follows Eastern time, the UP has a sliver of Central time along its border with Wisconsin.
  • Tennessee: Just like Kentucky, Tennessee is divided into two distinct time zones. The majority of the western half of the state, including Nashville, is on Central. The eastern half of the state, including Chattanooga, is on Eastern time.

Alaska

Alaska is the largest state in the country, so it only stands to reason that it is in two time zones. But did you know that Alaska actually has a time zone all its own? This, called the Alaska time zone, covers almost every piece of the state.

The exceptions in Alaska are the Aleutian Islands and St. Lawrence Island, which are in the Hawaii-Aleutian time zone.