Year-Round Daylight Saving Time vs Standard Time
Ana Marie Schick: Resident Sleep Expert and Certified Health Coach • Apr 11, 2025

Key Takeaways
Clock changes don’t just shift daylight—they disrupt how your body keeps time.
- Switching between Daylight Saving Time and Standard Time can disrupt sleep schedules, leading to short-term fatigue and reduced well-being.
- The biannual time change has sparked ongoing debate, with many experts questioning whether year-round Standard Time would better support sleep and health.
- Daylight Saving Time pushes winter sunrises later, with some regions seeing daylight after 8:30 a.m., which can make mornings feel harder.
- Standard Time creates earlier summer sunrises, sometimes before 4:30 a.m., which can impact early-morning light exposure.
- Consistent light timing matters—stable schedules and morning light exposure help reduce the sleep disruption caused by clock changes.
Are you tired of constantly struggling with your sleep schedule due to time changes? You're not alone.
Every year, the “fall back” and “spring forward” of the clocks, flipping the Daylight Saving Time (DST) switch on and off, wreaks havoc on our sleep patterns, leaving many of us feeling groggy, irritable, and downright miserable, sometimes for extended periods.
These time changes disrupt our internal clocks, potentially negatively affecting our health and overall well-being.
The incoming Administration is advocating for a permanent end to time changes. They suggest the country cease its biannual ritual of falling back and springing forward.
This move has garnered broad support in the past, with many recognizing the disruptions caused by the changing of time. However, it is currently unclear on their positions of which time is best - Standard or Daylight Saving Time.
In this blog, we’ll look at the benefits of staying on Daylight Saving Time or staying on Standard Time permanently.
What is Standard Time & What is Daylight Saving Time?
Most states currently use Standard Time from November to March. In March, most states “spring forward” one hour to Daylight Saving Time, and this stays until November, when clocks “fall back” to Standard Time.
Daylight time involves advancing clocks to utilize longer daylight hours during the summer months, typically moving clocks forward in spring and back in autumn to extend evening daylight.
Image: DST Standard Time Calendar
Where Did Daylight Saving Time Come From?
The United States first used Daylight Saving Time (DST) during World War I to help the war effort and save energy. In theory, DST shifted more daylight into evening hours, reducing the need for electricity.
Since electricity was often generated by burning fuel, DST meant people would use less electricity and, therefore, less fuel.
In 1918, Congress passed the Standard Time Act, which included the implementation of DST. After the war, few people liked the DST law. So, in 1919, much to President Wilson’s chagrin, Congress repealed the act.
Wilson favored DST because he believed it provided people with more leisure time in the evenings and conserved energy due to the extended natural light.
During World War II, President Roosevelt reinstated Daylight Saving Time, which he called 'War Time' and made it year-round. This started in 1942 and continued until the war ended in 1945.
After the war, different parts of the country were allowed to choose whether or not to use Daylight Saving Time. Finally, in 1966, President Johnson passed a law that made it the same nationwide.
In 2022, the U.S. Senate passed a bill called the Sunshine Protection Act that would make daylight saving time permanent.
It stalled in the House of Representatives because lawmakers could not agree on whether to keep standard time or permanent daylight saving time.
Republicans, who now control both chambers of Congress, could revive the bill or introduce a new one.
Benefits of Standard Time Year-Round
Maintaining Standard Time year-round offers several benefits for health, safety, and overall well-being:
Supports Natural Sleep Cycles
Standard time aligns with the natural light-dark cycle, helping regulate the body’s internal clock (called circadian rhythm) and promoting better sleep quality and consistency.
Improves Physical Health
A stable sleep schedule and exposure to morning sunlight can reduce the risk of cardiovascular issues, strengthen the immune system, and support overall physical health.
Boosts Mental Health
Morning light exposure increases serotonin production, which helps improve mood, reduce stress, and support mental clarity throughout the day. [1]
Promotes Safety
Consistent sleep patterns and natural morning light reduce fatigue, improving safety on roads, at work, and in other activities that require focus and awareness.
Aligns with Human Biology
Standard time mirrors the sun’s natural rise and fall, helping to balance hormones like melatonin and cortisol, which play a crucial role in sleep, energy, and overall health.
Benefits of Daylight Saving Time Year-Round
Keeping Daylight Saving Time year-round also offers several benefits that can positively impact health, productivity, and daily life:
More Evening Daylight
Extended daylight in the evening allows for more time to enjoy outdoor activities, exercise, or spend quality time with family and friends after work or school.
Furthermore, people who identify as “night owls” find themselves enjoying more productivity with longer days as well.
Boosts Physical Activity
With more daylight in the evening, people are more likely to engage in outdoor activities such as walking, running, or playing sports, supporting physical health and fitness.
Improves Mental Health
Extra evening sunlight can help boost mood and reduce symptoms of seasonal depression by increasing exposure to natural light later in the day.
Increases Productivity
Longer daylight in the evening provides more opportunities to accomplish tasks, run errands, or participate in hobbies, leading to a more productive and fulfilling day.
Reduces Energy Use
With more daylight in the evening, there’s less need for artificial lighting, which may help lower energy consumption and reduce electricity costs.
Promotes Safety in the Evening
More daylight during evening commutes or activities can help reduce accidents and improve safety, as visibility is greater in natural light.
Compare Year-Round Daylight Savings Time vs Standard Time
The chart below compares DST and Standard Time across a few major metropolitan US cities; New York, Los Angeles, & Atlanta.
Circled are key times to consider how they may impact your daily life, not just your sleep schedule.
As an example, New Yorkers may not want the Sunrise to be at 4:25 am in the Summer on Standard Time. Similarly, they may not want Sunrise to be at 8:16 am in the Winter on DST.
Image: Daylight Saving Sunrise Sunset Times Chart
Final Thought
Arguments can be made for and against each time. From a sleep health perspective - what we welcome most is the national focus and attention being brought to sleep and its effects on physical and emotional health.
Ultimately, consistency is key to adopting the healthiest and most life-sustaining habits so we prefer no switching.
The change definitely damages our collective circadian rhythm. As for the issue of later or earlier sunrises and sunsets, everyone has an opinion and the country is understandably split on the issue.
Saving Time vs Standard Time FAQs
Why does Daylight Saving Time affect sleep more than Standard Time?
Daylight Saving Time shifts the clock forward, forcing your body to wake earlier while your internal circadian rhythm stays on the old schedule. That misalignment makes falling asleep and waking up feel harder than during Standard Time.
Does Daylight Saving Time impact health long-term?
Short-term disruptions are most noticeable, but repeated circadian misalignment from DST has been linked to increased sleep debt, mood changes, and cardiovascular stress, especially around the spring transition.
How long does it take to adjust after a time change?
Most people adjust within 3–7 days, though some may need up to two weeks depending on sleep habits, light exposure, and schedule consistency.
Does every region observe Daylight Saving Time?
No. Many regions do not observe DST, including most of Arizona, Hawaii, and large parts of the world, which remain on Standard Time year-round.
Peer-Reviewed Research References
-
Rishi, M. A., et al.
Daylight Saving Time: An American Academy of Sleep Medicine Position Statement.
Journal of Clinical Sleep Medicine, 2020.
Study Type: Professional Society Position Statement
Key Finding: The American Academy of Sleep Medicine recommends the elimination of Daylight Saving Time in favor of permanent standard time, citing evidence that circadian misalignment caused by clock changes negatively affects sleep, cardiovascular health, and overall public safety.
View Study
Source URL: https://jcsm.aasm.org/doi/10.5664/jcsm.8780








