Daylight savings what is the purpose

More than a century later, is it still needed? Hit play on the player above to hear the podcast and follow along with the transcript below. This transcript was automatically generated, and then edited for clarity in its current form. There may be some differences between the audio and the text. It's Sunday, November 7th. These Sunday episodes are special. We're bringing you more from in-depth stories you may have already heard.

In most of the United States, daylight savings time just ended. If you haven't yet, set your clocks back one hour.

The Department of Transportation says daylight savings time conserves energy, prevents traffic accidents and reduces crime. But sleep experts say the health consequences of our sleep being disrupted by daylight savings time, outweigh any benefits. All right, so I'm joined by health reporter, Adrianna Rodriguez.

Thank you so much for being here. Claire Thornton: So remind me, what is the definition of daylight saving time? Who's responsible for making sure that we keep doing daylight saving time, and when did daylight saving time even start? Adrianna Rodrig And then that continues on until the first Sunday of November. It was first enacted by the Federal Government during World War I as a way to conserve coal, but now the Department of Transportation is in charge of it and says that it reduces crime, and reduces traffic accidents, and it also saves energy.

Claire Thornton: And why do they say that? It does reduce crime. It does save energy and it prevents traffic accidents in certain parts of the year. So, I would argue, there are studies that show that right after the switch happens, there's actually an increase of traffic accidents, but then after that, because it increases daylight hours towards the end of the day, it decreases traffic accidents that way.

And also because it increases daylight towards the end of the day, it also decreases other things like having to turn your lights on, and having to do stuff like that, and just using natural sunlight. And the same thing impose with crime. I would say crime happens more so often during nighttime. And so when there's less darkness and there's more light, there's less crime. Claire Thornton: Okay. So we'll get more into the details later.

You reported that that may not necessarily be true throughout the past, like, years. What have been some different reasons why we've kept daylight saving time around, besides the World War I original reason. In , Hudson presented a paper to the Wellington Philosophical Society, proposing a 2-hour shift forward in October and a 2-hour shift back in March. There was interest in the idea, but it was never followed through.

In , independently from Hudson, British builder William Willett suggested setting the clocks ahead 20 minutes on each of the four Sundays in April, and switching them back by the same amount on each of the four Sundays in September, a total of eight time switches per year.

The first Daylight Saving Bill was drafted in , presented to Parliament several times, and examined by a select committee. However, many, especially farmers, opposed the idea, so the bill was never made into a law. It is not known if he was aware that his idea had become a reality seven years before his death in a small town in Ontario. Not everyone is in on the clock-changing frenzy. Virgin Islands, and the Northern Mariana Islands all opt out of daylight saving time.

Globally, the popularity of changing clocks varies as well. Most of North America, Europe, New Zealand, and a few regions of the Middle East are in on the annual shift, though each have different start and stop dates.

But the majority of Africa and Asia do not change their clocks. South America and Australia are split on the matter. Europe's participation, however, soon may change. In , the European Union voted to end the mandatory time shift , which previously spanned March and October. But that plan seems to be on hold for now: Member states were expected to decide by whether to stay on summer or winter time but negotiations have stalled as the bloc deals with fallout from both Brexit and the COVID pandemic.

For many, the change seems meddlesome, resulting in missed meetings and sleepy citizens. There may be even more severe effects. Some studies identified an increase in heart attacks that coincides with springing forward and a slight decrease when falling back. Other studies suggest the time change could be linked to an increase of fatal car accidents , though the effect is small relative to the total number of crashes each year. Still other concerns include impacts to the immune system due to the inevitable sleep loss.

What's more, many studies have questioned whether there have ever been energy savings at all. A study from the U. Department of Energy suggested that in the United States, an extra four weeks of daylight saving time saved about 0. But others conclude the situation is largely a wash: The later sunlight hours do often reduce electricity use during this time, but they also spur more intense use of air conditioning in the evening or greater energy demands to light up the dark mornings.

Even so, those impacts may be location specific. One study found that daylight saving time caused an increase in energy demand and pollution emissions in Indiana, while another found it led to slight reductions in energy use in Norway and Sweden. These days, arguments in favor of daylight saving time generally center on the boost the time shift gives to evening activities.

People tend to go outside when it's light after work—playing sports, going for walks, taking kids to the playground—rather than sitting on the couch.

Many outdoor industries, including golf and barbecue , have even promoted daylight saving time, which they say boosts profits. Kotchen and Laura E. Correction : The original version of this story misstated the President who signed the Uniform Time Act of It was Lyndon B.

Write to Olivia B. Waxman at olivia. By Olivia B. Related Stories. Already a print subscriber?