19 American states have enacted permanent DST legislation. But it is Congress that has the final say on the matter.
The US is one of about 70 countries worldwide that use Daylight Saving Time (DST), but Hawaii and most of Arizona don’t use it.
When Does DST Start and End in the USA?
In the US, Daylight Saving Time begins on the second Sunday in March and ends on the first Sunday in November, when clocks are turned back to standard time.
The change happens at 2 am local time.
Why do we have Daylight Saving Time?Will the US Abolish Clock Changes?
On July 14, 2026, the US House of Representatives passed the Sunshine Protection Act. However, for the bill to become law and allow states to observe DST year-round, it must also be approved by the Senate and signed into law by the President.
It now awaits consideration in the Senate, the upper chamber of the US Congress, where the measure has so far drawn both support and opposition.
It would push winter sunrises to an absurdly late hour (...) kids would either walk to school in the pitch black or schools would have to push back start times.
Senator Tom Cotton of Arkansas
The HillPresident Donald Trump has previously expressed support for ending seasonal clock changes and making DST permanent in the US.
If the Sunshine Protection Act is enacted, most of the United States would cease to change its clocks twice a year and would observe Daylight Saving Time year-round. Areas that currently do not observe DST would not be required to adopt it.
For now, current law only allows states to opt out of DST but not to follow it year-round. Some state laws regulating permanent Daylight Saving Time are dependent on both federal approval and their neighboring states adopting the same time change. This ensures consistency across state borders and avoids confusion in regions where commerce, transportation, and daily life depend on aligned time zones.
Will Donald Trump “lock the clock”?States That Want to “Ditch the Switch”
Currently, 19 states have passed legislation for permanent DST. Most likely, there are bills in other states too. More than 750 bills and resolutions have been considered at the state level advocating for year-round DST, according to the National Conference of State Legislatures .
Note: * In California, not included in the count above, voters approved Proposition 7, giving the Legislature authority to adopt permanent Daylight Saving Time if permitted by federal law.
Permanent Standard Time Also an Option
Meanwhile, a number of states are considering legislation that would end the seasonal time change but keep them on year-round standard time.
Any move to permanent DST requires national-level approval in the USA.
Because earlier permanent DST bills have stalled in the US Congress, there have been more recent efforts to focus on a move to permanent standard time instead. Any move to year-round standard time does not require national-level approval.
This is because under current federal law, which is codified in the Uniform Time Act (UTA) and its amendments, states cannot unilaterally adopt year-round DST. However, the UTA allows states to opt out of DST, that is, to stay on year-round Standard Time, but not to stay on DST permanently unless Congress changes the federal UTA statute.
Not All States Use DST
Almost all of the US states have yearly clock changes. The only exceptions are Hawaii and Arizona.
Hawaii observes Hawaii Standard Time (HST) all year.
Most of Arizona observes Mountain Standard Time (MST) year-round, except the Navajo Nation, because its territory extends into Utah and New Mexico—both states that observe DST.
Indiana decided to join the national DST regime in 2006 after abstaining from changing its clocks since 1970–a decision layered onto an already tangled and complex patchwork of time zones within the state.
None of the US dependencies use DST, including American Samoa, Guam, Puerto Rico, the Northern Mariana Islands, the US Minor Outlying Islands, and the US Virgin Islands.
History: When Did DST Start in the USA?
In 1916, during World War I, Germany became the first country to adopt DST to save energy for the war effort. Many countries across Europe soon followed suit. In the US, “Fast Time,” as it was called then, was first introduced in 1918. The initiative was sparked by Robert Garland, a Pittsburgh industrialist who had encountered the idea in the United Kingdom.
Only seven months later, DST was repealed. But some cities, including Pittsburgh, Boston, and New York, continued to use it.
Can DST make you sick?“War Time” and “Peace Time”
In 1942, at the height of World War II, President Franklin D. Roosevelt reintroduced the measure, instituting year-round Daylight Saving Time in the US. Referred to as “War Time,” DST was in force continuously from February 9, 1942 to September 30, 1945.
During this time, the US time zones were called “Eastern War Time,” “Mountain War Time,” “Central War Time,” and “Pacific War Time.” After the surrender of Japan in mid-August 1945, the time zones were relabeled “Peace Time.”
National DST Rules since 1966
From 1945 to 1966, there were no uniform rules for DST in the US. This caused widespread confusion, especially for trains, buses, and the broadcasting industry. As a result, the Uniform Time Act of 1966 was established. While granting US states the ability to opt out of DST, the law provided a framework for a nationwide, synchronized DST schedule, starting on the last Sunday of April and ending on the last Sunday of October.
Year-Round DST in 1973
During the 1973 oil embargo, the US Congress ordered a year-round DST period lasting from January 1974 to April 1975. The rationale was to study the effects of seasonal time change on energy consumption. Following staunch opposition from the public and the realization that the measure yielded only modest energy savings, the plan was soon amended to allow for a return to standard time during the winter months.
The pros and cons of DSTEnergy Policy Act of 2005
After the energy crisis was over in 1976, the United States DST schedule was revised several times throughout the years. From 1987 to 2006, the country observed DST for about seven months each year. The current schedule was introduced by the Energy Policy Act of 2005 and has been followed since 2007.
Daylight saving or daylight savings?While we diligently research and update our DST and time zone content, some of the information in the table above may be preliminary.