You may have noticed: the days are getting shorter, and the sun is setting earlier. And this weekend, Chicago will hit a milestone that signals fall is almost here, and daylight saving time is approaching.
That milestone? The final 7 p.m. sunset for seven months.
"The last 7 p.m. sunset will occur this weekend," NBC 5 Meteorologist Alicia Roman said Thursday.
Thursday, Sept. 12, the sun in the Chicago area will set at 7:04 p.m., according to the website timeanddate.com. By Sunday, Sept. 15, the sun will set at 7 p.m., the website said.
It's the last 7 p.m. sunset until March of 2025, the site showed.
By Sept. 30, the sun will set at 6:32 p.m. By the end of November, the skies will see a sunset as early as 4:30 p.m. That's because on Nov. 3, clocks will roll back one hour as part of daylight saving time.
As the time change for 2024 in Illinois approaches, here's what to know about "falling back."
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When do we change our clocks?
Under federal law, daylight saving time begins on the second Sunday in March, and runs through the first Sunday of November in most of the U.S.
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This year, that date falls on Nov. 3, with clocks rolling back one hour at 2 a.m. that morning.
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 "wartime." 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.
When will DST resume?
In 2025, daylight saving time will resume on March 9, with clocks springing forward then.
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.
When does fall 2024 begin?
Although meteorological fall begins on Sept. 1, the autumnal equinox -- or astronomical fall -- is Sept. 22.
"The autumnal equinox is an astronomical event that marks the start of autumn (or “fall”)," a post from the Old Farmers Almanac said. "In the Northern Hemisphere, the autumnal equinox occurs in September; in the Southern Hemisphere, it occurs in March."
"After the autumnal equinox, days become shorter than nights as the Sun continues to rise later and nightfall arrives earlier," the post continued. "This ends with the winter solstice, after which days start to grow longer once again."
