The essay below 
The Conversation, an online publication covering the latest research.
As people in the United States prepare to turn their clocks forward one hour on Sunday, March 12, 2023, I am reminded of the annual media coverage of the disruptions to daily life caused by the switch from standard time to daylight saving time. I find myself gearing up for the ritual.
About a third of Americans say they don’t look forward to these twice-yearly time changes. Also, about two-thirds want to do away with it entirely, 21% are unsure, and 16% want to keep the clock ticking back and forth.
But the impact goes beyond mere inconvenience. Researchers have found that “getting up early” each March is associated with serious negative health consequences, including an increase in heart attacks and sleep deprivation in her teens. In contrast, as my co-author and I noted in his 2020 commentary, the fall transition to standard time is not associated with these health effects.
As a professor of neurology and pediatrics and director of the sleep department at Vanderbilt University Medical Center, I have spent over five years researching the pros and cons of these biannual rituals. It became clear to me and many of my colleagues that the transition to daylight saving time each spring had health implications immediately after the clock changed and for the roughly eight months that Americans stay on daylight saving time.
Strong case for permanent standard time
Americans are divided on whether they prefer permanent daylight saving time or permanent standard time.
However, the two time shifts, though they may waver, are not equal. Standard time is closest to natural light, with the sun overhead at or near noon. On the other hand, during daylight saving time from March to November, due to daylight saving clock changes, natural light will appear one hour later in the morning and one hour later in the evening according to the time of day.
Morning light is essential for regulating your body’s natural rhythms. Wake up and be more alert. Morning light is also uplifting. A light box that mimics natural light is prescribed for use in the morning to treat seasonal affective disorder.
The exact reasons why light activates us and positively affects our mood are still unknown, but the effects of light on elevated levels of cortisol, a hormone that regulates stress responses, Or it may be due to the effect of light on the amygdala, which is part of the amygdala. Emotional brain.
Adolescents can also be chronically sleep deprived due to school, sports, and social activities. For example, many children arrive at school around 8:00 am or earlier. This means that many young people wake up and go to school in the dark during daylight saving time.
The body of evidence, as I testified at a congressional hearing in March 2022 and argued in the Sleep Research Society’s recent opinion, is a good example of the nationwide adoption of a permanent standard time. The American Medical Association recently called for a permanent standard time. And in late 2022, Mexico will adopt permanent standard time, citing benefits for health, productivity and energy savings.
The biggest advantage of daylight saving time is that it provides extra light in the late afternoon or early evening, depending on the season, for sports, shopping, or dining outside. Late exposure to light comes at a price. This long evening light delays the brain’s release of melatonin, a hormone that promotes sleepiness, disrupting sleep and reducing sleep overall.
Puberty also causes melatonin to be released late at night, which means teens are delayed in their natural signals to help them fall asleep, so adolescents are especially vulnerable to prolonged evening light. You become more susceptible to sleep disturbances.
“Western Edge” Effect
Geographical differences can also affect how daylight saving time affects people. One study showed that people living on the western edge of the time zone get light later in the morning and late at night and get less sleep than those living on the eastern edge of the time zone.
The study found that West End residents had higher rates of obesity, diabetes, heart disease, and breast cancer, lower per capita incomes, and higher health care costs. Other studies have found that the incidence of certain other cancers is higher at the western edge of the time zone.
Scientists believe these health problems are the result of a combination of chronic sleep deprivation and “circadian rhythm deviations.” Circadian misalignment refers to a timing mismatch between our biorhythms and the outside world. In other words, the timing of your daily work, school, or sleep routine is based on the clock, not the rising and falling of the sun.
A Brief History of Daylight Saving Time
Congress enacted year-round daylight saving time during World War I and World War II and during the energy crisis of the early 1970s.
The idea was that having extra light in the late afternoon could save energy by reducing the need for electric lighting. It has been largely proven to be inaccurate in the summer, as the need for air conditioning can also increase in the late afternoon.
Another argument for promoting daylight saving time is that more light at the end of the day reduces crime rates. This has been proven to be true, but the changes are very small and the health impacts seem to outweigh the benefits to society from lower crime rates.
After World War II, it was left to state governments to specify the start and end dates for daylight saving time. However, this created many railroad schedule and safety issues, so Congress passed the Uniform Hours Act in 1966. This law set the dates for daylight saving time nationwide from the last Sunday in April to the last Sunday in October. In 2007 Congress amended a law extending daylight saving time from the second Sunday in March to the first Sunday in November. This date is still valid.
However, the Uniform Time Act allows states and territories to opt out of daylight saving time. Arizona and Hawaii are on Permanent Standard Time, along with Puerto Rico, the US Virgin Islands, the Northern Mariana Islands, Guam, and American Samoa.
Many other states are now considering whether to stop retreating and leaping forward. Several states in the United States are considering legislation or resolutions to support permanent standard time, while many other states are considering or are considering adopting permanent daylight saving time. Permanent standard time laws and resolutions increased from 15% in 2021 to 31% in 2023.
In March 2022, the U.S. Senate passed the Sun Protection Act calling for permanent daylight saving time. However, the House did not advance the bill. Florida Senator Marco Rubio reintroduced the bill on March 1, 2023.
The surge in activity among states trying to get out of these biannual changes reflects an increasing number of people recognizing the downsides of the practice. It is now up to legislators to decide whether to end timeshifting altogether and choose permanent standard or daylight saving time.
This article originally appeared on The Conversation. Please read the original article.
