In the United States, DST (daylight saving time) began Sunday, 10 March 2019, ends Sunday 3 November 2019. On that day, at 2a local time, clocks “fall back” one hour to 1a, to ST (standard time).
In Europe, clocks are rolled back an hour on the last Sunday of October, which this year falls on 27 October. Regardless of the day, this time change from DST to standard time results in the gain of 1 hour of sleep.
While the loss or gain of 1 hour might sound like a negligible amount, research clearly shows it has significant ramifications for public health and safety, particularly after the switch to DST in the Spring. However, even the switch back to standard time can leave you feeling off-kilter for days or even weeks, as the body adapts to the earlier onset of darkness.
We have daylight saving time to give us more access to daylight hours, thereby reducing energy costs and promoting healthy outdoor activities.
While the original intention was that extending daylight hours during the Summer would result in energy savings, research shows it’s not saving us any money.
For starters, lighting is no longer the most significant portion of energy consumption, and extending daylight hours encourages greater use of air conditioning and heating, both of which use more energy than lighting. A study by Yale economist Matthew Kotchen and Laura Grant, PhD., concluded that:
“… contrary to the policy’s intent — DST increases residential electricity demand. Estimates of the overall increase are approximately 1 percent, but we find that the effect is not constant throughout the DST period. DST causes the greatest increase in electricity consumption in the fall, when estimates range between 2 and 4 percent.”
Dr. Kotchen notes when DST begins in the Spring, people are waking during the coldest and darkest part of the day, often turning up the heat to stay warm, and during long evening hours, more air conditioning is used, leading to an overall higher energy use. He told the NY-T’s “The way people use energy now is different from when daylight saving came about.”
Similarly, a 2018 meta-analysis of 44 different papers found that, on average, DST lowered electricity use by a mere 0.34%. Locations further from the Equator, with mild Summers and low cooling demands, may save energy, but geographical locations closer actually use more energy during DST.
Researchers have found people are less productive once DST is implemented.
A 2012 National Geographic article quoted Till Roenneberg, a Russian chronobiologist, who said most people show “drastically decreased productivity,” decreased quality of life, increased illness, and are “just plain tired” in the week after DST in the Spring.
Disruptions in our sleep pattern tend to cascade throughout the entire body. For instance, sleep helps reset your neural circuits that are impaired during sleep deprivation. With too little sleep, your cognitive flexibility suffers.
Research from the University of Washington found cognitive inflexibility even affects judges who are handing down sentences. On the Monday after DST in the Spring, longer sentences are imposed on people who have been found guilty.
A similar negative effect has been found in students. A 2015 study found DST adversely affected sleep patterns of high school students and their ability to be vigilant at school.
Other data suggest it may affect academic performance. Researchers compared 10 years of SAT scores from Indiana where only 15 of the state’s 92 counties moved their clocks forward during the study period. The data indicated SAT scores were 16% of a standard deviation lower in counties that adopted DST.
A note, 1 reason Indiana is used as a discussion model for DST is because it lies between Central and Eastern time zones. Geographically, it is actually in the Central zone, but in Y 2006 it adopted the standardized DST to align with Eastern standard time changes.
The decision has been controversial in Indiana, where the western part of the state wants to align with the Central zone, while the eastern part favors aligning with Ohio’s Eastern zone.
A 2019 article by Health.com also cites evidence linking DST to higher rates of depression diagnoses, cluster headaches and lower success rates among women undergoing in vitro fertilization.
In addition to the strong recommendation of getting 8 hours of sleep on a consistent basis, there are some other things you can do to mitigate the effects of the time change until the powers that be decide to eliminate it.
While the most adverse health effects are attributed to the Springtime switch to DST, the switch back to standard time in the Fall means the body has to get used to it getting dark earlier in the evening.
When “falling back” an hour, the following tips can be helpful:
•Gradually start going to bed earlier, say 30 mins earlier than usual Saturday, and another 30 mins earlier Sunday. This will help you get up earlier to maximize your exposure to daylight earlier in the morning rather than later in the evening.
Be particularly mindful of using electronic devices in the days prior to the switch-over. Research on teens shows that using electronics for 4 hours during the day can increase your risk of needing more than an hour to fall asleep by 49%.
So, if you have considered “unplugging” for a day or 2 the weekend of the time change is a perfect time to turn everything off, or cut down your use of electronics to a bare minimum so that you can optimize your sleep. You can also consider supplementing with melatonin if you have trouble falling asleep on an earlier schedule.
•Exercise in the mornings over the weekend, in accordance with your overall level of health and fitness.
•Eat dinner earlier and pay attention to your diet, making sure you are consuming plenty of fresh, whole foods, preferably organic, and minimal amounts of processed foods and fast foods; keep your sugar consumption low, especially fructose.
•Practice good sleep hygiene, including sleeping in complete darkness, checking your bedroom for electromagnetic fields, and keeping your bedroom temperature cool enough for optimal sleep.
Have a terrific weekend