You may wonder each year how many minutes of daylight people gain at various times of the year. That is a reasonable question, especially when you consider the adage “Fall back, spring forward.” Many of these answers in the United States depend on Daylight Saving Time (DST).
In early spring (or late winter), the majority of Americans lose an hour of sleep, while in late autumn, they gain an hour. Daylight Saving Time affects our sleeping patterns and, in part, the amount of sunlight we will see during business hours.
Undoubtedly, DST plays a significant role in our daily lives. Where did the concept originate, and why was it implemented? Perhaps most importantly, why does it continue to exist? Let’s investigate the rationale behind this century-old practise and determine the types of time changes that will occur this year.
When Do Days Begin to Grow Longer?
Between March and June, as the sun rises higher in the sky, we gain two additional minutes of daylight per day. After Daylight Saving Time (beginning on the second Sunday of March at 2:00 a.m.), it is simple to observe how much daylight is added each day. Typically, it is darker in the morning and brighter in the late afternoon. In addition, the longer the sun remains above the horizon, the greater a person’s latitude and distance from the equator.
In August, the daily loss of daylight begins to accelerate by two minutes until the winter solstice, which occurs between December 20 and December 23. At the solstice, the North Pole is most distant from the sun, resulting in the year’s shortest day. The longest day of the year occurs on June 21, the summer solstice, when the Northern Hemisphere is closest to the sun, resulting in the longest day of the year.
From the vernal equinox in March to the summer solstice in June, the Northern Hemisphere experiences an increase in daylight. This is the reason why people in Australia experience winter during what is summer for those living north of the equator.
Why Daylight Saving Time Alters
Simply put, the Earth controls this change, specifically the tilt of the Earth’s axis. The axis on which the Earth spins is tilted at 23.5 degrees relative to the axis around which it revolves every 365 days – or 366 days during a Leap Year. The tilted axis determines the number of daylight hours each day. Depending on a person’s latitude, daylight hours vary.
For instance, the tilted regions of Earth receive more than 12 hours of sunlight per day. Conversely, regions facing away from the sun receive less sunlight. The degree to which a portion of the Earth is tilted toward or away from the sun varies throughout the year as the Earth revolves around the sun.
You can track the precise sunrise and sunset times for your location and even view a graph of day length on a number of websites. This can help you determine how many hours of sunlight each day will have.
The majority of the world uses DST to keep track of when we begin gaining and losing daylight hours during the spring, summer, and fall seasons. But what is the precise function and history of DST?
The origins and intent of Daylight Saving Time
Some people attribute the idea to Benjamin Franklin because of an essay he wrote in 1784. Others assert that either Canada or Germany initiated Daylight Saving Time in the early twentieth century. Regardless, the United States government needed a way to increase production while conserving energy during World War I, and Daylight Saving Time, which takes advantage of the later hours of sunlight from April to October, appeared to be an ideal solution. During World War II, when the United States joined the war effort, the federal government required states to observe Daylight Saving Time.
After World War II, the federal government permitted states to observe Daylight Saving Time. The Uniform Time Act was passed by Congress in 1966, standardising the length of Daylight Saving Time. Due to the 2005 passage of the Energy Policy Act, Daylight Saving Time has been extended by four weeks, from the second Sunday in March to the first Sunday in November.
The stated purpose of Daylight Saving Time is to conserve energy. In light of this, Congress enacted the Energy Policy Act to save 10,000 barrels of oil per day. Legislators anticipated a decrease in oil consumption as a result of a reduction in the amount of energy used by businesses during daylight hours. Unfortunately, the amount of energy savings, if any, is nearly impossible to quantify. Regardless of energy savings from fossil fuels, Daylight Saving Time continues in the majority of the United States.
Luminescence and Human Health
The “loss of an hour of sleep” is a common complaint about Daylight Saving Time. Joseph S. Takahashi, Ph.D., Chair of the Department of Neuroscience at UT Southwestern, investigated the physiological effects of desynchronization. This twice-yearly desynchronization of our body clocks has been linked to increased health risks such as depression, obesity, heart attack, cancer, and even car accidents, according to the UT Southwestern Medical Center.
Every cell in the human body is capable of keeping track of time. Changes in daily routines result in sleep deprivation, memory loss, learning difficulties, and impaired cognitive function. Dr. Takahashi’s laboratory discovered the CLOCK gene, “the first circadian gene in mammals,” in 1997. Mutated CLOCK genes may delay circadian functions, resulting in metabolic, behavioural, and cognitive dysfunctions.
In 2016, Dr. Takahashi’s lab identified the first genes that regulate sleep in mice. The study identified two genes in mice that regulate the amount of rapid eye movement (REM) and non-REM sleep required.
A healthy sleep pattern requires long periods of non-REM sleep, during which the brain is not processing memories or dreaming. Nearly twenty percent of the population suffers from sleeping disorders, and these findings suggest ways to improve their sleep hygiene.
Therefore, Daylight Saving Time and other environmental factors play a significant role in disrupting human health.
Where Does Daylight Savings Time Still Apply?
Currently, 48 states observe Daylight Saving Time. Arizona opted out of the practise in 1968 as a result of the excessive summer heat. NASA reports that the Navajo Nation in northeastern Arizona observes daylight saving time.
Due to its tropical latitude, Hawaii has never observed Daylight Saving Time under the Uniform Time Act. In 1933, the state legislature briefly instituted Daylight Saving Time. The state, however, repealed the law within three weeks. In addition, the climate in Hawaii is relatively stable, so Daylight Saving Time had little impact on energy consumption.
Every election cycle seems to bring up the topic of Daylight Saving Time again. In 2020, Senators Marco Rubio and Rick Scott of Florida introduced the Sunshine Protection Act, a contemporary illustration of how Daylight Saving Time continues to be an important topic of political and scientific discourse. I
n the meantime, the European Union has voted to end biannual time changes in 2019. Several states in the United States are considering similar legislation due to the health risks.
This year, Daylight Saving Time begins on March 13 and ends on November 6. Consider going to bed earlier and adjusting your clocks and alarms in advance.