Title: Daylight saving time in the United States
Content:  city, state and municipality. As of 1954, only California and Nevada had statewide DST west of the Mississippi, and only a few cities between Nevada and St. Louis. In the 1964 Official Railway Guide, 21 of the 48 contiguous states had no DST anywhere. By 1965, there were 18 states that observed daylight saving for six months each year, 18 states that didn't have formal policies but held cities or towns with their own daylight saving standards and another 12 states that didn't implement daylight saving at all. Meanwhile, portions of North Dakota and Texas observed a sort of "reverse" daylight saving time, essentially setting their clocks back an hour rather than moving them forward.
Title: Daylight saving time in the United States
Content:  Daylight saving time in the United States is the practice of setting the clock forward by one hour when there is longer daylight during the day, so that evenings have more daylight and mornings have less. Most areas of the United States observe daylight saving time (DST), the exceptions being Arizona (except for the Navajo, who do observe daylight saving time on tribal lands), Hawaii, and the overseas territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the United States Virgin Islands. The Uniform Time Act of 1966 established the system of uniform daylight saving time throughout the US. In the U.S., daylight saving time 
Title: Daylight saving time in the United States
Content:  used daylight saving time in 1966 to start it on the last Sunday in April and end it on the last Sunday in October. In 1967, Arizona and Michigan became the first states to exempt themselves from DST (Michigan would begin observing DST in 1972). In 1972, the act was amended (P.L. 92-267), allowing those states split between time zones to exempt either the entire state or that part of the state lying within a different time zone. The newly created Department of Transportation (DOT) was given power to enforce the law. , the following states and territories are not observing DST: Arizona, Hawaii, American Samoa, Guam, The Northern Mariana Islands, Puerto Rico, and the Virgin Islands.
Title: Standard time in the United States
Content:  In summer 1960 April–October Daylight Time was nearly universal in Pennsylvania, Maryland, Delaware and states east and north of there. In Minnesota, Iowa, Missouri, Kentucky and Virginia and states north and east of there, some areas had it and some did not. Except for California and Nevada, which had April-Sept Daylight Time, 99% of the rest of the country used Standard Time year-round. (The Official Guide says "State law prohibits the observance of "Daylight Saving" time in Kentucky but Anchorage, Louisville and Shelbyville will advance their clocks one hour from Central Standard time for the period April 24 to October 29, inclusive.") In the middle 1960s the airline and other transportation industries lobbied for uniformity of Daylight dates in the United States.
Title: Daylight saving time by country
Content:  Since 2018, several U.S. states have passed laws to abolish seasonal changes and adopt permanent DST, but these laws cannot take effect without approval from the federal government. States may freely choose whether to observe DST or not, but if they observe it they must follow the national schedule, and changing their standard time also requires approval from the federal government.
Title: Uniform Time Act
Content:  The state of Hawaii has never observed daylight saving, even during World War II when "War Time" was observed by other states as an energy saving measure. Observance of daylight saving in varied by county in Indiana until 2 April 2006 when the entire state once again observed DST, a first since Congress repealed the Standard Time Act of 1918. The commonwealths of the Northern Mariana Islands and Puerto Rico and the territories of American Samoa, Guam, and U.S. Virgin Islands also do not observe Daylight Saving Time. Arizona has not observed daylight saving since the year following the enactment of the Uniform Time Act of 1966. Native American nations within Arizona may choose. The Navajo Nation has chosen to use daylight saving throughout its territory, which includes parts of New Mexico and Utah where daylight saving is observed. The Hopi Nation has chosen not to observe daylight saving in territory is surrounded entirely by the Arizona portion of the Navajo Nation,
Title: Daylight saving time in the Americas
Content:  Canada and the United States of America use daylight saving time on a wide scale, with only a few states/provinces and parts thereof opting out of the practice or adopting it year-round without the twice yearly switch. The United States territories of Puerto Rico and the Virgin Islands remain in Atlantic Standard Time (AST) all year long, meaning that clocks in these regions match those in New York City during the summer and Bermuda in the winter. Since 2007, in areas of Canada and the United States of America in which it is used, daylight saving time begins on the second Sunday of March and ends on the first Sunday of November.
Title: Daylight saving time in the United States
Content:  Daylight saving time is less useful in Florida than in other states because its southern location leads to less variation in day length between winter and summer. Without DST, Miami, for instance, would experience sunrise and sunset times throughout the year similar to cities such as Honolulu or Hong Kong, neither of which observe DST. There is opposition to DST in Florida. State senator Bill Posey introduced a bill in March 2008 to abolish daylight time in the state and keep Florida on year-round standard time. Because Florida straddles two time zones, the Florida legislature has the option of returning all or part of the state to standard time along time zone boundaries.
Title: Standard time in the United States
Content:  area of the state lying in one time zone. Indiana chose to exempt the portion of the state lying in the Eastern Time Zone; however, that exemption was eliminated in 2006 and the entire state of Indiana now observes DST, leaving Arizona (with the exception of the Navajo Nation) and Hawaii as the only two states not to observe DST. On July 8, 1986, President Ronald Reagan signed the Federal Fire Prevention and Control Act of 1986 into law that contained a daylight saving rider authored by Senator Slade Gorton (R-WA). The starting date of DST was amended to the first Sunday in April effective in 1987. DST continued to end on the last Sunday in October. While 
Title: Daylight saving time in the United States
Content:  Under the Uniform Time Act, moving an area on or off DST is accomplished through legal action at the state level. Congress gives states two options: to either opt out of DST entirely or to switch to DST the second Sunday in March. Some states require legislation while others require executive action such as a governor's executive order. Information on procedures required in a specific state may be obtained from that state's legislature or governor's office. Although it may exempt itself, if a state decides to observe DST, the dates of observance must comply with federal legislation.

Question: what states do not allow daylight savings time?
Answer: Navajo.
Hawaii.
Arizona.