Last Sunday, Nov. 1, the clocks wound back from 2:00 a.m. to 1:00 a.m., marking the end of daylight savings time for this year. As we return to standard time, several questions come up: Why do we have daylight savings time? Why do we keep it? Should we keep it?
First, daylight savings time should be defined. According to Britannica, daylight savings time refers to the practice of “advancing clocks, so as to extend daylight hours during conventional waking time in the summer months.” For example, as CBS news reported, on Oct. 31, the sunrise and sunset in Boston were at 7:16 AM and 5:39 PM, respectively. On Nov. 1, they were 6:17 AM and 4:37 PM, true to the change by an hour of the clocks. But why did we start doing this?
As Britannica and the BBC explain, Benjamin Franklin is most commonly credited with coming up with the basic idea in 1784, with the idea of saving the use of artificial light, which were candles at the time. However, this idea was not brought to implementation until much later, in 1916—during WWI—by Germany, with the goal of saving energy consumption from lighting by extending the duration when there was daylight in the evening. Then, Britain adopted a similar policy. It was in 1918 that America first implemented daylight savings time for similar reasons. However, it was repealed the following year, with states free to continue observing it. The next implementation in the U.S. would occur during WWII, when the U.S. implemented year-round daylight savings time, also to save energy, with the national implementation ending in 1945. Since then, in the U.S., year-round daylight savings time has only been implemented once in 1974, following the 1973 energy crisis.
As the U.S. Department of Transportation explains, it was only in 1966 that the Uniform Time Act was passed, creating the uniform system of daylight savings time in the U.S. we currently have. Even then, not all of the U.S. observes daylight savings time: under the Uniform Time Act, states are free to opt out of the system of daylight savings time, though they are not allowed to observe it year-round, and must follow the national dates for starting and ending daylight savings time. Currently, in the U.S., most of Arizona and Hawaii and territories such as Guam, American Samoa, and Puerto Rico continue to observe standard time only.
One of the advantages of daylight savings time can be inferred from who Time magazine reported to have lobbied for the Uniform Time Act: the Chamber of Commerce. As the magazine and Britannica explain, if there is still daylight, from the savings, when workers leave their workplaces, this would lead them to shop more after work, boosting the economy through retail sales.
Its effects on health and safety are more complicated. Britannica writes that additional daylight hours in the evening appear to encourage more outdoor activity, potentially contributing to public health. However, it also notes a UNC report’s findings of an increased risk of heart attacks on the Monday after the clock shift in the spring. The BBC also reported heart attacks as a major health concern regarding shifting the clock, and added that researchers in Finland found an 8% increase in hospitalizations for strokes over the two days after time shifts. Furthermore, it reported potential concerns regarding mental health as well, citing a 2017 study using data from the Danish Psychiatric Central Research Register’s findings that the number of unipolar depressive episodes rose 11% following the spring clock shift.
The consequences on safety are also not clear-cut. Britannica notes extra daylight can promote safety, as spring time changes are found to be associated with reduced numbers of robberies and decreased risks of accidents involving pedestrians, potentially due to improved visibility. At the same time, Britannica points out that daylight savings also increases deaths from car accidents as the risk of car accidents being fatal increases between 5% and 6.5%. The BBC reports similar concerns regarding car accidents, citing findings by researchers in Spain that fatal accidents increased by 30% on the day of the spring time change and 16% on the day of the fall time change. Both Britannica and the BBC also note concerns regarding increased workplace injuries on the Monday after the spring time change.
The effects on energy consumption, the reason for which daylight savings was first implemented, are also mixed. The BBC reports that research shows mixed results for whether the U.S. is saving energy from it. They even reported that Arizona, one of the states opting out of daylight savings time, would have done it also to save energy, as implementing daylight savings hours appeared to increase use of air conditioning, thus more energy. Britannica also referred to a study by the National Bureau of Economic Research showing that daylight savings time increased electricity consumption in households in southern Indiana, which also mentions simulation results showing a trade-off between lighting and temperature control.
The BBC reports there have also been efforts to stop observing daylight savings time. The European Commission proposed this in 2018, though the European Council and European Parliament failed to agree, and thus the proposition is not implemented. The Guardian also reported the Congress in Mexico abolished daylight savings time in most of the country. The BBC adds that in March 2023, the Sunshine Protection Act, which aims to turn daylight savings time permanent, was introduced. Its effect would be to keep the time as it is during the summer, one hour ahead of standard time. However, the BBC has noted that this has also not passed yet.
In fact, some experts seem to prefer the option of permanent standard time over permanent daylight savings time, contrary to the Sunshine Protection Act: According to the BBC, the American Academy of Sleep Medicine wrote in favor of permanent standard time. It should also be noted that, as Britannica explains, permanent daylight savings time was highly unpopular when it was implemented in the past: at the end of WWII, the proportion of citizens in favor of keeping it was 17%, and in the 1970s implementation, 53% opposed continuing to use it. One of the reasons for objection appears to have been that children would be heading to school before sunrise, because the sun would only rise after 9:00 a.m. in some areas.
According to the Pew Research Center, about a third of the countries worldwide observe daylight savings, and half now only used to. Perhaps it is time to reconsider our own relationship with daylight and our clocks.
