Which States Do Not Observe Daylight Saving Time?
Meta description: Learn which U.S. states do not observe Daylight Saving Time, why Hawaii and most of Arizona stay on standard time, and how the Navajo Nation is an exception.
In the United States, Hawaii and most of Arizona do not observe Daylight Saving Time. Their clocks stay on standard time throughout the year, while most states move clocks forward in spring and back in fall. Arizona has an important exception: the Navajo Nation observes Daylight Saving Time, even though much of the surrounding state does not. Understanding these rules helps explain why local times can differ across state lines and even within Arizona.
States That Do Not Observe Daylight Saving Time
Two states do not follow the seasonal clock changes used by most of the country:
- Hawaii stays on Hawaii-Aleutian Standard Time year-round.
- Arizona stays on Mountain Standard Time year-round in most areas. The Navajo Nation observes Daylight Saving Time.
In everyday conversation, people often say these states “do not recognize” Daylight Saving Time. More precisely, they do not observe the seasonal time change. Federal law allows states to exempt themselves from Daylight Saving Time, but it does not let a state adopt permanent daylight time without federal approval.
U.S. territories including Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa, and the Northern Mariana Islands also do not observe Daylight Saving Time. They are not states, so they are separate from the answer to which states skip the clock change.
Hawaii: No Seasonal Clock Changes
Hawaii does not observe Daylight Saving Time. The state remains on Hawaii-Aleutian Standard Time throughout the year, so residents do not set clocks forward in spring or back in fall. Hawaii’s location near the equator means daylight hours do not vary as dramatically by season as they do in many northern states. The seasonal shift would provide less benefit there.
Hawaii’s fixed schedule also means its time difference from the mainland changes during the year. When much of the United States observes Daylight Saving Time, Hawaii is generally two hours behind Pacific Daylight Time. During standard time, it is generally three hours behind Pacific Standard Time. The exact comparison depends on which mainland time zone is being considered.
Arizona: Standard Time With a Major Exception
Most of Arizona remains on Mountain Standard Time all year. Because the state does not move its clocks forward in spring, its relationship to neighboring states changes seasonally. In winter, Arizona is generally aligned with Mountain Standard Time. During the months when nearby states observe Daylight Saving Time, most of Arizona shares the same clock time as Pacific Daylight Time.
The Navajo Nation is the key exception. The Navajo Nation observes Daylight Saving Time, and its land extends across parts of Arizona, New Mexico, and Utah. As a result, some communities in northeastern Arizona change clocks while much of the state does not. The Hopi Reservation, which is surrounded by Navajo land within Arizona, does not observe Daylight Saving Time. This creates a patchwork of local time rules that can affect travel and scheduling.
For visitors, a map alone may not be enough to determine the local time in this region. A route may pass through areas that follow different clock schedules, and the time shown on a phone can depend on location settings or network updates. Travelers should check the local time for a specific destination, particularly when crossing reservation boundaries or planning appointments.
Why Do Some States Skip Daylight Saving Time?
Daylight Saving Time shifts an hour of daylight from the morning to the evening during part of the year. Supporters have often argued that the longer evening daylight can benefit recreation, commerce, or energy use. Opponents point to disrupted sleep, scheduling complications, and questions about whether the practice saves energy consistently.
Geography is part of the explanation for Hawaii and Arizona. Hawaii’s tropical latitude produces relatively modest seasonal changes in daylight. In Arizona, intense summer heat is one reason commonly cited for keeping the clock schedule stable: moving clocks forward would shift more activity into the hotter part of the evening by the clock. Local preferences and historical decisions also shape each state’s policy.
There is no single reason that explains every community’s position. The practical effects of a time change depend on climate, daylight patterns, work and school schedules, and how closely a community is connected to neighboring regions that change clocks.
How Federal Law Governs Daylight Saving Time
The federal Uniform Time Act of 1966 established a nationwide framework for standard time and seasonal clock changes. Under the law, states that observe Daylight Saving Time follow a common start and end schedule. States can exempt themselves from observing it by state law. Hawaii and Arizona have chosen that option, with the Navajo Nation’s separate practice creating the Arizona exception.
Federal law distinguishes between opting out of the seasonal change and adopting permanent Daylight Saving Time. A state may remain on standard time year-round, but changing to permanent daylight time requires an act of Congress. This is why proposals to “end the clock change” can involve different legal approaches and are not automatically implemented when a state passes a resolution or bill.
The U.S. Department of Transportation oversees time-zone boundaries and administers aspects of the federal time system. The National Institute of Standards and Technology provides information on U.S. time and the dates when Daylight Saving Time begins and ends.
When Do Most States Change Their Clocks?
Most U.S. states begin Daylight Saving Time on the second Sunday in March and return to standard time on the first Sunday in November. At the spring change, clocks move ahead one hour, typically at 2 a.m. local time. At the fall change, clocks move back one hour, repeating an hour of local time.
Hawaii and most of Arizona do not make either seasonal adjustment. Their clocks remain on standard time, so the difference between them and states that observe Daylight Saving Time shifts when those states change clocks.
| Location | Observes Daylight Saving Time? | Typical time-zone practice |
|---|---|---|
| Hawaii | No | Hawaii-Aleutian Standard Time year-round |
| Most of Arizona | No | Mountain Standard Time year-round |
| Navajo Nation in Arizona | Yes | Changes clocks with Daylight Saving Time |
| Most other states | Yes | Changes clocks in spring and fall |
| U.S. territories | No | Practices vary by territory; they generally do not make seasonal changes |
How Time Differences Change Through the Year
When clocks change in states that observe Daylight Saving Time, the time difference between those states and Hawaii or most of Arizona changes too. This can affect work calls, flight planning, television schedules, online events, and family conversations across state lines.
For example, Arizona’s clock may match California’s during the months California is on Pacific Daylight Time. In winter, California returns to Pacific Standard Time, while most of Arizona remains on Mountain Standard Time, making Arizona one hour ahead. Hawaii’s offset from the mainland also varies depending on whether the mainland is using standard or daylight time.
These are general comparisons, not substitutes for checking a particular city and date. Arizona’s Navajo Nation exception, federal and local time-zone boundaries, and changes to time-zone rules can affect the result. Calendar apps and reliable time-zone services usually account for those factors when a location is selected correctly.
Common Misunderstandings About States and Daylight Saving Time
“Arizona never changes time anywhere.”
This is an oversimplification. Most of Arizona does not change clocks, but the Navajo Nation observes Daylight Saving Time. The state’s local time can therefore vary by community and season.
“Hawaii and Arizona are always on the same time.”
They are not. Hawaii uses Hawaii-Aleutian Standard Time, while most of Arizona uses Mountain Standard Time. The difference between them is usually three hours, but it can vary when daylight time is in effect elsewhere or when comparing different locations and dates.
“A state can switch to permanent Daylight Saving Time whenever it wants.”
Under current federal law, a state can exempt itself from Daylight Saving Time and stay on standard time year-round. Moving to permanent daylight time requires congressional action. A state-level proposal alone does not necessarily change the clocks.
“Daylight Saving Time is the same as a time zone.”
A time zone is a geographic region that uses a shared standard time. Daylight Saving Time is a seasonal adjustment to the clocks used in many, but not all, parts of the country. A location’s time zone and its observance of Daylight Saving Time are related but distinct details.
Practical Tips for Scheduling Across State Lines
- Use a city, not just a state name. This matters especially in Arizona, where local rules differ.
- Check the date as well as the location. Time differences can change in March and November.
- Confirm important appointments. For flights, remote meetings, medical visits, and event start times, verify the time zone shown on the official confirmation.
- Keep device settings current. Automatic time-zone updates help, but location permissions and network settings can affect what a device displays.
- Allow extra time when traveling. A short drive across a boundary may change the local clock, especially around the Navajo Nation.
Reliable Sources for Current Time Rules
For official background, the U.S. Department of Transportation’s Daylight Saving Time information explains federal rules and state options. The National Institute of Standards and Technology’s Daylight Saving Time page provides details about the seasonal schedule. For travel in northeastern Arizona, checking the destination’s local government or the Navajo Nation’s current information can help clarify local observance.
The short answer is straightforward: Hawaii and most of Arizona do not observe Daylight Saving Time. The main complication is the Navajo Nation, which does observe it. Because the rules affect time differences throughout the year, checking the specific destination and date is the safest way to schedule across state lines.