Most people can name four US time zones. The real number is nine, fourteen states are split across two of them, and several million Americans live somewhere that never changes its clocks. This page is the map of all of it — and the jumping-off point for the detailed guides to each piece.
The nine official US time zones
Six zones cover the fifty states. Three more cover the territories. All nine are defined in federal regulation, and only some of them observe Daylight Saving Time.
| Zone | Standard | DST | Where |
|---|---|---|---|
| Eastern | UTC−5 | Yes (UTC−4) | New York, Florida, most of the East Coast |
| Central | UTC−6 | Yes (UTC−5) | Chicago, Texas, the Plains |
| Mountain | UTC−7 | Yes (UTC−6), except most of Arizona | Denver, Salt Lake City, Phoenix |
| Pacific | UTC−8 | Yes (UTC−7) | California, Washington, Nevada |
| Alaska | UTC−9 | Yes (UTC−8) | Nearly all of Alaska |
| Hawaii–Aleutian | UTC−10 | Aleutians only | Hawaii, western Aleutian Islands |
| Atlantic | UTC−4 | No | Puerto Rico, US Virgin Islands |
| Samoa | UTC−11 | No | American Samoa |
| Chamorro | UTC+10 | No | Guam, Northern Mariana Islands |
End to end, that is a 21-hour spread — wide enough that two people can both be in the United States and be on different calendar dates at the same moment. For the full breakdown, including the uninhabited possessions that sit outside all nine zones, see how many time zones the US really has.
The fourteen states split across two zones
A time zone boundary almost never follows a state line. It follows trade, travel and habit — where people actually do business. That leaves fourteen states with an internal time zone border.
| State | Zones | The smaller side |
|---|---|---|
| Alaska | Alaska / Hawaii–Aleutian | Western Aleutian Islands |
| Florida | Eastern / Central | Western Panhandle, incl. Pensacola |
| Idaho | Mountain / Pacific | Northern counties, incl. Coeur d'Alene |
| Indiana | Eastern / Central | Northwest and southwest corners |
| Kansas | Central / Mountain | Sherman, Wallace, Greeley, Hamilton |
| Kentucky | Eastern / Central | Western third, incl. Paducah |
| Michigan | Eastern / Central | Gogebic, Iron, Dickinson, Menominee |
| Nebraska | Central / Mountain | Panhandle counties, incl. Scottsbluff |
| Nevada | Pacific / Mountain | West Wendover, on the Utah border |
| North Dakota | Central / Mountain | Southwestern corner |
| Oregon | Pacific / Mountain | Malheur County, incl. Ontario |
| South Dakota | Central / Mountain | Western half |
| Tennessee | Eastern / Central | East Tennessee, incl. Knoxville |
| Texas | Central / Mountain | El Paso and Hudspeth counties |
Some sources count thirteen rather than fourteen, because Alaska's split is between Alaska Time and Hawaii–Aleutian Time rather than a mainland boundary. The full list of split states covers each one in turn.
The splits in detail
- Florida — the line roughly follows the Apalachicola River, and Pensacola runs an hour behind Miami.
- Texas — El Paso trades with New Mexico and Ciudad Juárez, so it keeps their clock, not Dallas's.
- Indiana — the state did not adopt DST statewide until 2006, and Indianapolis and Gary still sit in different zones.
- Michigan and Kentucky — both drifted eastward city by city rather than by any single federal decision.
- Oregon and Idaho — two separate boundaries in one corner of the country, neither following the state line.
- Nebraska, Kansas and the Dakotas — the four split states nobody talks about, and Nebraska's boundary is still politically live.
- Alaska — four zones until 1983, when a fight over the state capital collapsed them into two.
The places that never change their clocks
Springing forward is not universal. Two states and every populated territory sit on standard time all year.
- Arizona opted out in 1968 — the argument was air conditioning, not farming.
- Hawaii is close enough to the tropics that there is little seasonal daylight to redistribute.
- Puerto Rico, Guam, American Samoa and the other territories were never brought under the federal DST mandate.
The exceptions have exceptions. The Navajo Nation observes DST across all three states its land covers, including the Arizona portion — and the Hopi Reservation, sitting entirely inside Navajo land, does not. That nesting is also why the famous Four Corners story is not true.
Why the map looks like this
US time zones were not designed by a government. They came out of the railroads in 1883, which needed a schedule that worked across towns each keeping their own solar time. Every boundary since has been adjusted by petition — a county here, a city there — which is why the lines wander. China made the opposite choice, and runs a country the same width on a single clock.
Working across the zones
Two practical notes. Abbreviations are less help than they look: IST means three different countries, and EST is only correct for four months of the year. And if you are scheduling around office closures, the federal holiday calendar through 2036 lists the observed date for every year, which is not always the calendar date.
When you need an actual answer rather than a rule, put both cities into the time zone converter or the meeting planner — they resolve the county-level cases and the DST offsets for you.
Frequently asked questions
How many time zones does the United States have?
Nine. Six cover the fifty states — Eastern, Central, Mountain, Pacific, Alaska and Hawaii–Aleutian — and three cover the territories: Atlantic (Puerto Rico, US Virgin Islands), Samoa (American Samoa) and Chamorro (Guam, Northern Mariana Islands). Only some of the nine observe Daylight Saving Time.
Do all US states have just one time zone?
No — fourteen of them span two. Alaska, Florida, Idaho, Indiana, Kansas, Kentucky, Michigan, Nebraska, Nevada, North Dakota, Oregon, South Dakota, Tennessee and Texas all have an internal time zone border, usually cutting off a corner or a handful of counties rather than dividing the state evenly.
Which US states don't observe Daylight Saving Time?
Hawaii and most of Arizona, plus every populated US territory — Puerto Rico, the US Virgin Islands, Guam, the Northern Mariana Islands and American Samoa. The Navajo Nation is the notable exception inside Arizona: it does observe DST, because its land also covers Utah and New Mexico.
Why don't US time zone boundaries follow state lines?
Because they were never drawn to. The zones came out of the railroads in 1883 and have been adjusted ever since by local petition, following trade and travel ties. El Paso keeps New Mexico's clock, Oregon's Malheur County keeps Idaho's, and the Florida Panhandle keeps Alabama's.