AMNA NAWAZ: Last month, almost the entire country performed the biannual ritual of changing our clocks, in this case, springing forward to start daylight saving time.

But, on Capitol Hill today, lawmakers debated getting rid of this practice once and for all.

William Brangham explains.

SEN. LISA BLUNT ROCHESTER (D-DE): I know I speak for many Americans when I say it's time, it's time to figure this out.

SEN. TED CRUZ (R-TX): Congress has the authority to end this outdated and harmful practice.

SEN. EDWARD MARKEY (D-MA): We just have to make daylight saving time permanent, in my opinion, one way or the other, or at least get more -- we need more sunshine.

WILLIAM BRANGHAM: Today's hearing, named after Cher's hit song "If I Could Turn Back Time" examined a bipartisan bill called the Sunshine Protection Act, which would change our current system where, in March, most states spring forward to daylight saving time and then in November fall back to standard time.

This law would establish permanent daylight saving time nationwide, no more switching.

SEN. RICK SCOTT (R-FL): The American people are sick and tired of changing their clocks twice a year.

It's confusing, unnecessary and completely outdated.

SCOTT YATES, Founder, Lock The Clock: My name is Scott Yates.

I have been reading, writing and testifying about this for nearly a decade and I have this recommendation.

WILLIAM BRANGHAM: Scott Yates, founder of the Lock the Clock campaign, has been on a yearslong mission to ditch the switch.

He cites evidence that in the days immediately following the time change, human health suffers.

SCOTT YATES: Peer-reviewed studies consistently show that heart attacks go up, strokes, car crashes.

Even miscarriages spike in those days following the spring switch.

Study from the University of Vienna found deaths overall just increased by 3 percent in those couple of days after the change.

WILLIAM BRANGHAM: You have been like a modern-day Sisyphus trying to push this rock up a hill.

Now you're here in Washington.

Do you think this is finally going to be the day that you win the argument?

SCOTT YATES: Well, I hope so.

WILLIAM BRANGHAM: According to polls, it's an idea that's gaining popularity.

President Trump has voiced support.

But the right solution, permanent daylight saving time or permanent standard time, has been debated for years.

And today's raft of testimony reflected the competing issues.

Jay Karen represents the golf industry, which favors permanent daylight saving time, which would extend daylight for all those late afternoons on the links.

JAY KAREN, National Golf Course Owners Association: Golf thrives on what we call recreational daylight, the overlap of sunlight and people's availability to be outdoors.

WILLIAM BRANGHAM: But then Dr. Karin Johnson, representing the American Academy of Sleep Medicine, testified that the darker mornings you get with daylight saving is terrible for sleep.

The academy recommends permanent standard time.

DR. KARIN JOHNSON, American Academy of Sleep Medicine: Morning light and healthy sleep are known treatments for depression.

On the other hand poor sleep increases the risk of drug use, alcohol use and other risk-taking behaviors.

WILLIAM BRANGHAM: And Dr. David Harkey of the Insurance Institute for Highway Safety says that, in terms of accidents and public safety, darkness is dangerous.

DR. DAVID HARKEY, Insurance Institute for Highway Safety: The clearest takeaway from this research is that there is a strong relationship between increased darkness and fatal crashes, particularly for pedestrians and bicyclists.

WILLIAM BRANGHAM: So how did we get here?

Where did this idea come from that I remember being told as a kid that this was to help the farmers of America?

DAVID PRERAU, Daylight Saving Historian: That is one of the myths that I don't understand about, because it's 100 percent wrong.

WILLIAM BRANGHAM: David Prerau has written two books on the strange history of why we change our clocks.

It started after the Germans changed their clocks during World War I to save energy.

The U.S. later copied that and kept it up for several decades.

In the 1960s, President Johnson signed a law setting official dates for the switching back and forth.

But during an energy crisis in the '70s, President Nixon reversed that, establishing a year-round daylight saving time.

But pretty soon the country saw the darker side of daylight saving, which adds more sunshine to our evening, but steals it from the morning.

DAVID PRERAU: What happened was, it seemed OK until the middle of winter in 1974, when it became very unpopular very quickly.

People really dislike the winter daylight saving time.

They dislike 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.

WILLIAM BRANGHAM: President Ford then reversed course, and we went back to changing clocks twice a year, which brings us back to today's debate.

Should we stop switching?

And, if so, which time do we choose?

SEN. TED CRUZ: It's a question of what do you care about more, sunshine and joy and fun and money, or health, mental health, physical health?

And the honest answer for most people is, gosh, I care about all that stuff.

So that's not an easy trade-off.

WILLIAM BRANGHAM: This isn't the first time this legislation has been introduced, and the chances of the bill clearing the Senate and being taken up by the House remain slim.

For the "PBS News Hour," I'm William Brangham.