When Does Time Change in Illinois? Here's What to Know About Daylight Saving Time

In just over a week, Illinois residents - and most Americans - will change their clocks, ushering in another hour of sunlight in exchange for losing a little sleep.

At 2 a.m. on March 12, the clocks will jump directly to 3 a.m., differing from the autumn time change when clocks "fall back" to 1 a.m. upon the conclusion of daylight saving time.

While there is stalled legislation that would make daylight saving time permanent on a national level, the time change will be happening this year regardless of any decision regarding the legislation.

With the time to spring forward just over a week away, here's what to know about daylight saving time this year:

When does daylight saving time start?

Under provisions of the Energy Policy Act of 2005, which amended the Uniform Time Act of 1966, daylight saving time will begin on the second Sunday in March, which in 2023 will fall on March 12.

The time change will take place at 2 a.m.

When does daylight saving time end?

Daylight saving time will end at 2 a.m. on Nov. 5, 2023, in what is known as the annual "fall back."

What is daylight saving time?

Daylight saving time is a changing of the clocks that typically begins in spring and ends in fall in what is often referred to as "spring forward" and "fall back."

Under the conditions of the Energy Policy Act of 2005, daylight saving time starts on the second Sunday in March and ends on the first Sunday in November.

On those days, clocks either shift forward or backward one hour.

But it wasn't always that way.

Clocks used to spring ahead on the first Sunday in April and remained that way until the final Sunday in October, but a change was put in place in part to allow children to trick-or-treat in more daylight.

In the United States, daylight saving time lasts for a total of 34 weeks, running from early-to-mid March to the beginning of November in states that observe it.

Some people like to credit Benjamin Franklin as the inventor of daylight saving time when he wrote in a 1784 essay about saving candles and saying, "Early to bed, early to rise makes a man healthy, wealthy and wise." But that was meant more as satire than a serious consideration.

Germany was the first to adopt daylight saving time on May 1, 1916, during World War I as a way to conserve fuel. The rest of Europe followed soon after.

The United States didn't adopt daylight saving time until March 19, 1918. It was unpopular and abolished after World War I.

On Feb. 9 ,1942, Franklin Roosevelt instituted a year-round daylight saving time, which he called "war time." This lasted until Sept. 30, 1945.

Daylight saving time didn't become standard in the US until the passage of the Uniform Time Act of 1966, which mandated standard time across the country within established time zones. It stated that clocks would advance one hour at 2 a.m. on the last Sunday in April and turn back one hour at 2 a.m. on the last Sunday in October.

States could still exempt themselves from daylight saving time, as long as the entire state did so. In the 1970s, due to the 1973 oil embargo, Congress enacted a trial period of year-round daylight saving time from January 1974 to April 1975 in order to conserve energy.

What's the deal with the Sunshine Protection Act?

Under legislation unanimously passed by the Senate last year known as the Sunshine Protection Act, the seasonal changing of clocks would effectively be eliminated in the U.S., except for Hawaii and parts of Arizona.

Despite passage in the Senate, the bill has stalled in the House, where it remained in a committee until the expiration of the previous Congress.

Overall, thoughts on the potential shift vary.

The Sunshine Protection Act was introduced by Sen. Marco Rubio, R-Fla., who suggested it would reduce crime, encourage kids to play outside and lower the risk of heart attacks and car accidents.

"There’s some strong science behind it that is now showing and making people aware of the harm that clock-switching has," Rubio said on the Senate floor in March, NBC News reported.

A 2020 study found that fatal traffic accidents in the U.S. rose 6% in the week after daylight saving started. Other studies have found that the switch to daylight saving brings small increases in workplace injuries and medical errors in the days following the change. A 2019 study, meanwhile, found that the risk of heart attacks went up in the week after clocks sprung forward, though other research did not find such an increase.

The research overall is mixed, however, and the American Academy of Sleep Medicine supports the opposite switch to permanent standard time, as research shows that bodies function best with more sunlight in the morning.

“I have received calls from constituents who prefer permanent standard time because they have safety concerns for children who have to wait too long in the dark during winter for the school bus," said Rep. Jan Schakowsky, of Illinois' 9th Congressional District and a Democratic member of the House Energy and Commerce Committee, where the bill currently sits.

Schakowsky said she has also heard from constituents who prefer longer daylight hours and as a result support permanent daylight saving time.

While the congresswoman said there does not seem to be a consensus among voters, she stated "we know that the majority of Americans do not want to keep switching the clocks back and forth."

According to the AASM, which is based in Illinois, standard time may be more aligned with our body's internal clock.

"The daily cycle of natural light and darkness is the most powerful timing cue to synchronize our body’s internal clock," AASM says. "When we receive more light in the morning and darkness in the evening, our bodies and nature are better aligned, making it easier to wake up for our daily activities and easier to fall asleep at night. Daylight saving time disrupts our internal clock, leading to sleep loss and poor sleep quality, which in turn lead to negative health consequences."

"More populous cities would be impacted by darker mornings as well – with permanent daylight saving time, sunrise wouldn’t occur until 8:20 a.m. in New York City in January. In Los Angeles, sunrise in January would be at almost 8 a.m., and in Minneapolis, sunrise would be at nearly 9 a.m."

Which states observe daylight saving time?

Nearly every U.S. state observes daylight saving time, with the exceptions of Arizona (although some Native American tribes do observe DST in their territories) and Hawaii. U.S. territories, including Puerto Rico, American Samoa, Guam and the U.S. Virgin Islands, do not observe daylight saving time.

What is standard time?

According to the website Time and Date, standard time is the local time in a country or region when daylight saving time is not in use.

"More than 60% of the countries in the world use standard time all year," the site says. "The remaining countries use DST during the summer months, generally setting clocks forward one hour from standard time."

According to the AASM, it's standard time that more closely matches our body's internal clock.

"The daily cycle of natural light and darkness is the most powerful timing cue to synchronize our body’s internal clock," the Illinois-based organization says. "When we receive more light in the morning and darkness in the evening, our bodies and nature are better aligned, making it easier to wake up for our daily activities and easier to fall asleep at night. Daylight saving time disrupts our internal clock, leading to sleep loss and poor sleep quality, which in turn lead to negative health consequences."

Which is better? Here's what sleep experts say

Regardless of whether or not daylight saving time is made permanent or standard time takes over, Dr. Kathy Sexton-Radek, a consultant for the American Academy of Sleep Medicine's Public Safety Committee and professor of psychology with a special interest in sleep medicine at Elmhurst College, said the changing of clocks can have negative effects on the body.

The shift can "skew or put off-center the normal systems that trigger structures within our mind, within our brain, that tell us through hormone cues and brain chemistry when it's time to be awake and when it's time to be asleep," she told NBC Chicago earlier this year.

Such shifts can cause mood changes, fatigue, concentration issues, and more, Sexton-Radek said.

"Light is the most powerful timing cue for the human body clock,” Erin Flynn-Evans, who has a doctorate in health and medical science and is director of the NASA Ames Research Center Fatigue Countermeasures Laboratory, said in a statement. “Shifting to permanent daylight saving time in the winter would result in more darkness in the morning and more light in the evening, leading to misalignment between the body’s daily rhythm and the timing of routine social obligations, like work or school. That has the potential to make it harder for most people to fall asleep at night, disrupting sleep quality and leading to sleep loss, which can negatively impact health and safety.”

While the legislation on the table is currently to make daylight saving time permanent, the AASM says it's permanent standard time that should be adopted instead, with one reason being to ensure safety for morning commutes.

"For morning commuters and children heading off to school, dark mornings caused by permanent daylight saving time pose numerous safety concerns," the AASM says. "This would be especially problematic during the winter months when days grow increasingly shorter."

"More darkness during early morning commutes may also contribute to an increased risk of traffic fatalities, according to studies," the organization goes on to say.

Sleep experts also argue that permanent daylight saving time would "disproportionately" affect people living in the northern part of the U.S.

"Some parts of Montana, North Dakota and Michigan would not see sunrise until after 9:30 a.m. during the winter months," the AASM said, if the country adopted permanent daylight saving time.

"More populous cities would be impacted by darker mornings as well – with permanent daylight saving time, sunrise wouldn’t occur until 8:20 a.m. in New York City in January. In Los Angeles, sunrise in January would be at almost 8 a.m., and in Minneapolis, sunrise would be at nearly 9 a.m."

Sleep experts at the organization go on to say that seasonal time changes overall are unfavorable to health. According to the AASM, the changes have been linked to an increase in stroke, hospital admissions and cardiovascular events.

"One study found a reduction in the rate of cardiovascular events during standard time in particular, suggesting that the chronic effects of daylight saving time may lead to a higher risk of adverse health problems when compared with standard time," it says.

According to the Department of Transportation, daylight saving time has a number of benefits. The DOT's website highlights the following:

• It saves energy. During Daylight Saving Time, the sun sets one hour later in the evenings, so the need to use electricity for household lighting and appliances is reduced. People tend to spend more time outside in the evenings during Daylight Saving Time, which reduces the need to use electricity in the home. Also, because the sunrise is very early in the morning during the summer months, most people will awake after the sun has already risen, which means they turn on fewer lights in their homes.
• It saves lives and prevents traffic injuries. During Daylight Saving Time, more people travel to and from school and work and complete errands during the daylight.
• It reduces crime. During Daylight Saving Time, more people are out conducting their affairs during the daylight rather than at night, when more crime occurs.

Which is correct: daylight saving time or daylight savings time?

According to thesaurus.com, the correct answer is: daylight saving time.

"Daylight-saving time (singular saving) is technically the correct version: the practice is saving daylight," the website says. "Still, daylight-savings time (with the plural savings) is so commonly used that it’s become an accepted variant of daylight-saving time."

Thesaurus.com says the "s" at the end of the phrase may have caught on because the plural of "saving" is often used when referring to money -- for example, a savings account.

"Then there’s the question of the hyphen," the explanation continues, "Some leave it off while others include it. We hyphenate because daylight-saving together modifies the word time that directly follows."