The history of daylight saving time and its effect on our health Transcript

This weekend, nearly all of us will set our clocks back one hour as part of the twice-a-year ritual of alternating between daylight saving time and standard time. But as William Brangham reports, there’s a movement underway to do away with this process once and for all.

Like almost all of us in the country, Scott Yates is about to set his clocks back one hour as we do every fall when the nation falls back to standard time. But Yates, like a growing number of Americans, is sick of it.

If somebody snuck into your house and changed your alarm clocks, so it went off an hour earlier than your body was expecting, you would be so mad.

Absolutely.

Yet, the government does it every year. We’re all so sleep-deprived, we don’t really know how to respond.

In every state except Arizona and Hawaii, clocks spring forward in early March to start daylight saving time and fall back in early November to begin standard time. A few years ago, Yates’ wife said, “Stop complaining about it and do something,” so he started a blog, compiling various studies and reports about why we change our clocks, what the economic impacts are, even some pretty striking evidence that this back and forth switching can harm people’s health.

You can compare what’s the heart attack data on the Monday after the spring forward time change in places that do have the change, and then places that don’t have the change like Arizona. They don’t have a spike in heart attacks on that Monday morning after in Arizona, and they do everywhere else, and so it becomes really pretty clear evidence. It’s really just a glitch in the way that we operate the clocks, and it’s a deadly glitch.

Yates became something of a go-to expert, testifying before different state legislatures.

My name is Scott Yates.

Even trying an unsuccessful run for Congress in his home state of Colorado, all focused on this issue of stopping the biannual change. It’s an idea that is gaining popularity. In the last few years, 19 states have passed legislation to do away with the switch and make daylight saving time permanent, even though federal law prohibits states from doing that. But then earlier this year in the Senate, the Bipartisan Sunshine Protection Act was introduced. It would make daylight saving time permanent starting next year.

Daylight saving time brings sunshine, smiles and savings.

I’ve watched sporting events be called, youth sporting events be called in the middle or near the end of the game before it’s actually concluded because there’s not enough lights.

Any parent who has worked so hard to get a newborn or a toddler on a regular sleeping schedule understands the absolute chaos changing our clocks creates and for no good reason.

The Senate unanimously passed the bill in March, but it’s stuck in the House over debate on which time, daylight or standard, is the one to lock our clocks on. So if there is this groundswell to stop switching, why do we even do it in the first place? Where did this idea come from that I remember being told as a kid that this was to help the farmers of America.

That is one of the myths that I don’t understand about because it’s 100% wrong, 100% wrong.

David Prerau has written two books on the strange history of why we change our clocks. He also worked in the Federal Department of Transportation helping craft this policy in the 1970s. During World War I, the Germans changed their clocks to preserve energy during the summer months, and in 1918, the U.S. tried the same and kept it up through both world wars.

Not only, by the way, did it save energy, but it did other things. Like it left an extra hour in the evening where people can come home from work and tend to victory gardens, which would grow some food extra for the war effort.

For the next few decades, cities and states could choose what to do with their own clocks. But in the ’60s, President Johnson signed a law setting specific dates for daylight saving time. It said if states chose to do it had to be statewide.

In the short term, we face a problem.

Then in the early ’70s trying to ease an energy crisis, President Nixon signed a law which locked the clocks on daylight saving time year round. But pretty soon, Americans saw the darker side to daylight saving, which adds more sunshine to the evening, but takes it from the morning.

What happened was it seemed okay until the middle of winter in 1974 when it became very unpopular very quickly. People really disliked the winter daylight saving time. They disliked having to get up in the pitch dark, having to commute to work in the dark, and having to send their kids to school in the dark.

President Ford then reversed course, and we went back to changing clocks twice a year, which brings us to today in this movement to go back to permanent daylight saving time. According to one poll earlier this year, nearly six in 10 Americans want to ditch the switching. While that could mean longer days in the fall and winter, giving us more light to enjoy the great outdoors, it’s partly why the golf industry supports the move. Some health experts say, “Not so fast.”

Waking up in the pitch black is not normal for our bodies.

Beth Mallow is a pediatric neurologist at Vanderbilt Medical Center. She says, “Yes, later sunsets are great, but stealing that morning light can have real detrimental effects.”

Morning light is key in terms of helping people have a normal healthy sleep cycle and be able to get to bed at night.

So the light that you’re exposed to in the morning can not just have an effect on you in the morning, but it can have an effect 12, 14, 16 hours later on your sleep.

Correct. I wish in an ideal world we could have light at both ends, but if we have to choose where to get our light, where’s the most healthy part of the day to get our light? It’s actually in the mornings for the reasons I mentioned, because it helps us synchronize our bodies and our brains to what’s going on in our environment.

She argues that on balance, if we have to pick one option, only permanent standard time would be the healthiest option. After his years of studying the issue, David Prerau argues for keeping the current system and helping people manage the transitions better. He says, “Remember, permanent daylight saving gives you sunnier evenings, but much darker mornings.”

You would have morning, for example, in places like New York, Chicago, Dallas, Denver, San Francisco, the sun would rise at 8:30. In places like Detroit, Indianapolis, Minneapolis, Seattle, the sun would rise at 9:00 AM. So if the sun is rising at 8:30 or 9:00, almost everybody is going to work into school in the dark. That’s a pretty big negative a lot of people didn’t like, and they didn’t like it in 1974.

While Congress and state legislatures debate the issue, we can all enjoy a couple more of these long autumn evenings before Sunday morning when we fall back into darkness. For the PBS News Hour, I’m William Brangham in Washington D.C.

This is far too controversial a question for me to express my own opinion. Thank you, William.