Daylight saving time is almost over. Here’s what to know.

Millions of Americans will gain an hour of sleep this weekend when the twice-a-year time change commonly known as daylight savings ends for 2026. Most of the U.S. will “fall back” an hour when the clocks change at 2 a.m. on the first Sunday of November.

Here’s what to know about what’s formally known as daylight saving time as it ends for the year:

What is daylight saving time, and why do we have it?

Daylight saving time is the period during the year, from March to early November, when the majority of the U.S. operates one hour ahead of standard time.

The move effectively “saves” an hour of daylight from the morning and adds it to the evening during the spring and summer months when the days are the longest. In the fall and winter months, when the days are shorter, the U.S. returns to standard time, with daylight coming earlier in the morning.

For example, in Boston on Saturday, before the time change, the sun will rise at 7:16 a.m. and set at 5:39 p.m., according to the National Weather Service. On Sunday, back on standard time, sunrise will be at 6:17 a.m. and sunset will be at 4:37 p.m.

The U.S. first adopted daylight saving time in 1918 during World War I as an effort to conserve fuel after Europe implemented its own time change, according to the Congressional Research Service. After the war, Congress repealed the clock switch but gave states the option to continue observing it.

During World War II and the 1970s energy crisis, Congress brought year-round daylight saving time to the U.S., again with the goal of reducing energy consumption. These experiments didn’t last long.

After the war, the U.S. let states and municipalities decide for themselves if they wanted to keep daylight saving time and when to observe it. (Congress didn’t establish a uniform start and end for the time change until 1966.) In the ’70s, continuous daylight saving time was stopped before reaching the 10-month mark.

Will the U.S. move to year-round daylight saving time?

Earlier this year, legislation to once again make daylight saving time last all year long cleared a major hurdle in Congress. The bill, called the Sunshine Protection Act, passed the House in July and went to the Senate. The legislation would also let states opt out of daylight saving time altogether before the law takes effect.

President Trump, who supports the bill, accused a fellow Republican, Arkansas Sen. Tom Cotton, of holding up the legislation. Mr. Trump even posted to social media what he said was Cotton’s cellphone number and urged people to call the senator to express their support for the measure.

In response, Cotton noted Congress has tried permanent daylight saving time before, only to go back to the twice-yearly time change “once Americans experienced absurdly late sunrises in the winter.”

There is a ticking clock for the Senate to take action on the bill. The legislation and any other bills awaiting approval in Congress are set to expire in early January when the new class of lawmakers elected in Tuesday’s midterm elections takes office.

If the bill does die, the effort to change daylight saving time will have to start over and be approved by the House and the Senate before it can go to the president.

Did the time change today?

The time won’t change until this weekend.

For 2026, the end of daylight saving time comes during the overnight hours after Halloween, giving revelers an extra hour of enjoying late-night costume parties — or an extra hour of sleep to recover from their fun.

But for parents of young children, the time change can be more of a trick and less of a treat, potentially disrupting their kids’ sleep schedules until they adjust.

What day and time does daylight saving time end in November 2026?

Daylight saving time officially ends at 2 a.m. local time on Sunday, Nov. 1.

Americans have been “falling back” on the first Sunday of November since 2007, when the most recent changes to daylight saving time took effect. A 2005 law moved the end date from the last Sunday of October.

Do we lose or gain an hour when daylight saving time ends?

Most Americans will gain an hour when daylight saving time ends, making up for the hour they lost when the clocks “sprang forward” in March.

When will daylight saving time start again in 2027?

Daylight saving time is set to begin in 2027 on Sunday, March 14, at 2 a.m. local time. The time change starts on the second Sunday of March, which falls on such a late date next year because the month starts on a Monday. In 2026, daylight saving time started on March 8.

The start date was also changed in 2007 to extend the length of daylight saving time, which previously began on the first Sunday of April.

Which states don’t do daylight saving time?

Daylight saving time is observed in every state except for Hawaii and most of Arizona. The Navajo Nation, which is located in part of Arizona, observes the time change to stay on the same time as their communities in the neighboring states of New Mexico and Utah, according to the tribe.

The U.S. territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands also don’t observe daylight saving time.

Will my phone change for daylight saving time automatically?

Phones should change overnight to display the correct time if they’re set to update automatically.

Apple, Google and Samsung have support pages with instructions for changing the clocks on their devices. Carriers like Simple Mobile and Straight Talk have also posted steps online for checking the settings on other phones.