When is the time change? – NBC Chicago

The official start of autumn is just around the corner and with it a series of changes – including the time of day.

Autumn begins this weekend, with the autumn equinox on Sunday, but the time change will not happen immediately.

Here's what you need to know about fall and the time change in the Chicago area:

When is the first day of autumn?

Fall officially begins on September 22, 2024 at 7:44 a.m. CT.

According to the Farmer's Almanac, this is the time when the astronomical event that marks the beginning of autumn occurs. In the Northern Hemisphere, the autumnal equinox occurs in September, and in the Southern Hemisphere, in March.

When does daylight saving time end?

Illinois and several other U.S. states are currently observing Daylight Saving Time, which began in the spring. But that time is about to end, as the clocks go back during this time of year, giving residents a much-coveted extra hour of sleep.

But when does this happen?

The federal government stipulates that the clocks go back every year on the first Sunday in November. In 2024, this day falls on November 3rd.

What is daylight saving time?

Daylight saving time is a time change that usually begins in the spring and ends in the fall. Under the terms of the Energy Policy Act of 2005, daylight saving time begins on the second Sunday in March and ends on the first Sunday in November. On these days, clocks are either moved forward or back one hour.

Outside of daylight saving time, the time is called standard time.

Currently, Illinois alternates between the two times. When the state changes to daylight saving time, it changes to standard time when it changes to fall time.

According to the Time and Date website, standard time is the local time of a country or region that does not observe daylight saving time.

“More than 60% of the world's countries use standard time year-round,” the website says. “The remaining countries use daylight saving time and generally set their clocks forward one hour from standard time.”

In which states is there no daylight saving time?

The annual time change takes place in Illinois and almost all US states, with two exceptions:

Arizona (although some Native American tribes observe daylight saving time in their territories) and Hawaii.

Some U.S. territories, including Puerto Rico, American Samoa, Guam, and the U.S. Virgin Islands, also do not observe daylight saving time.

Which is better: daylight saving time or standard time?

Previously, a draft law had called for the introduction of permanent summer time, but it ultimately failed.

However, sleep experts have long questioned the healthiness of daylight saving time.

The American Academy of Sleep Medicine has been pushing for a permanent switch to standard time for several years.

“By diverting people's internal clocks from the natural environment, daylight saving time increases risks to our physical health, mental well-being and public safety,” said Dr. M. Adeel Rishi, chair of the AASM Public Safety Committee and a pulmonary, sleep medicine and critical care physician at Indiana University Health in Indianapolis, in a statement. “Permanent standard time is the optimal choice for health and safety.”

Experts have cited a “growing body of evidence” in recent years.

“Permanent standard time helps synchronize the body clock with the rising and setting of the sun,” said Dr. James A. Rowley, president of the AASM, in a press release. “This natural synchronization is optimal for healthy sleep, and sleep is essential for health, mood, performance and safety.”

This also reflects the opinion of other organizations, including the National Sleep Foundation, which said: “Seasonal time changes are harmful to sleep and should be abolished.”

How early will it be sunset?

You may have noticed: The days are getting shorter and the sun is setting earlier. Chicago already experienced its last 7 p.m. sunset of the year, on September 15th.

On September 30th the sun will set at 18:32

In the run-up to the change to daylight saving time, sunsets slowly end earlier and with the end of daylight saving time the sun finally sets at 4:41 p.m.

At the end of November the sun can already be seen in the sky at 4:30 p.m.

What is the autumn equinox?

The autumn equinox, also known as the fall equinox or September equinox, marks the halfway point between summer and winter – also known as autumn.

On its journey around the sun, the earth moves at a certain angle.

For most of the year, the Earth's axis is tilted either toward or away from the sun, meaning the sun's heat and light fall unevenly on the northern and southern halves of the planet.

When the Northern Hemisphere is tilted toward the Sun, it is called the summer solstice. This marks the first day of summer in the north and the first day of winter in the south.

One hundred and eighty days later, when the southern hemisphere is tilted toward the sun, it is called the winter solstice. This marks the first day of winter in the north and the first day of summer in the south.

The midpoints between the solstices are the autumn and spring equinoxes. The word equinox comes from two Latin words meaning “equal” and “night.” This is because at the equinox, day and night are almost the same length – although depending on your location on Earth, it may be a few minutes longer. This works out to approximately 12 hours of day followed by 12 hours of night.