As the days get shorter and the nights get longer, the time is coming to “fall back.” But not all states observe daylight saving time, and some have introduced legislation to eliminate it entirely.

Here’s what to know as DST approaches.

When do we change the clocks?

Under federal law, those states participating in daylight saving time will roll their clocks back at 2 a.m. on the first Sunday in November, which this year falls on Nov. 3.

Clocks will then spring forward on the second Sunday in March 2025, which will fall on March 9.

What is daylight saving time?

Daylight saving time is a changing of the clocks that typically begins in spring and ends in fall. 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.

When not in daylight saving time, the time is known as standard time.

As it stands, Illinois shifts between the two. The “spring forward” is when the state enters daylight saving time, and the “fall back” marks a return to 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.”

When does daylight saving time end?

Currently, Illinois and several states across the U.S. are in daylight saving time, which began in spring. But that will soon come to an end as clocks “fall back” this season, giving residents a coveted extra hour of sleep.

But when does that happen?

The federal government mandates clocks roll back on the first Sunday of November each year. In 2024, that falls on Nov. 3.

Do all states participate in daylight saving time?

Most states do participate in the twice-annual clock changes, but Arizona and Hawaii do not, having opted out of the practice.

Can states decide their own time?

Under provisions of the Uniform Time Act, states have the option of either participating in daylight saving time, committing to springing forward and rolling back clocks on the appointed days, or to opt out of the practice altogether, keeping year-round standard time.

States cannot opt to keep daylight saving time on a permanent basis under provisions of the act.

However, many states have passed legislation that would convert them to year-round daylight saving time should Congress alter the Uniform Time Act. According to KGW, Alabama, Colorado, Florida, Georgia, Louisiana, Maine, Minnesota, Missouri, Oklahoma, South Carolina and Tennessee all have laws on the books that would allow for the states to observe permanent daylight saving time if Congress would allow them to do so.

Does Illinois observe DST?

Yes. Clocks in Illinois “fall back” each year in November, and “spring forward” in March.

While there have been laws proposed to observe permanent daylight saving time in Illinois, none have passed the General Assembly, according to lawmakers.

The same is true in Indiana, where most of the state operates on Eastern time and the northwestern counties of Lake, Porter, LaPorte, Newton and Jasper counties operate on Central time.

In Michigan, a referendum was proposed for voters that would have allowed for a vote on daylight saving time, but it was referred to committee and did not pass in time for the 2024 election.