President Donald Trump's campaign to make daylight saving time permanent has escalated into a personal feud with the lone Republican blocking it in the Senate — and it has revived debate over a policy the United States has tried, and abandoned, before.

The last national experiment came in 1974, when President Richard Nixon put year-round daylight saving time into place. The author of this column, then living with his wife Louise just outside Lansing, Michigan, recalls that the sun did not rise until nine in the morning that January; commuters drove to work in full darkness, children waited for the school bus under streetlights, and eight schoolchildren were killed in traffic accidents in Florida alone.

When Nixon first flipped the switch, 79 percent of Americans supported year-round daylight saving time. By the end of 1974, support had collapsed to 42 percent, and President Gerald Ford signed the repeal that October.

According to the author, the biggest force behind the idea of year-round daylight saving time has been the golf course industry. William Willett, the Englishman who invented the notion of shifting the clocks, was an avid golfer, and the scheme's original purpose was to give players another hour on the course in the evening. In 1986, the golf industry told Congress that extending daylight saving time by just one more month would bring the industry at least an additional $200 million a year; it got its extension. It was, the argument goes, all about the money and had nothing to do with science.

Now, fifty-two years later, Congress is poised to repeat the experiment under heavy pressure from Trump, who reported that just last year he made nearly $395 million from people playing golf at his 16 golf courses.

The House passed the Sunshine Protection Act on July 14 by a vote of 308 to 117, and the bill has been sitting in the Senate ever since. The measure would keep clocks on daylight saving time year-round, ending the twice-yearly switch — and pushing winter sunrises an hour later on the clock. The legislator blocking it is Senator Tom Cotton, which means the Senate is where the bill's fate now rests. Trump responded by publishing Cotton's personal cell phone number and suggesting that people convey his message to the senator, in a post on his own social media platform:

"The PGA TOUR, as an example, needs more Daylight in the afternoon in order to finish their Tournaments. Likewise, regular Golfers, Tennis Players, Hunters and, perhaps most importantly, Farmers who want more Daylight to play or work."

Farmers, for the record, have disliked daylight saving time since 1918 — because, as the old line goes, cows don't read clocks. Golf, however, is another story, and, like the fossil fuel industry, the author contends, it is all about the money. This time around, though, opponents of the change have science that was largely unknown — though certainly intuited — when Nixon was president.

Three weeks ago, the Canadian Medical Association Journal published a peer-reviewed analysis by a team of sleep scientists, psychiatrists, and economists who examined the entire body of research. Their conclusion was blunt, as co-author Ralph Mistlberger, a chronobiologist at Simon Fraser University, explained:

"Morning light is the primary environmental time cue that aligns our biological clocks to local time. If morning light is delayed, our clocks and all the rhythms they control are delayed."

Human bodies do not run on the clock on the wall. They are calibrated and recalibrated every day by exposure to sunlight, which resets the cluster of cells behind the optic nerve that then tells every organ in the body what time it is and what it needs to be doing. Daylight saving time pushes that signal back an hour in winter, when much of the country — particularly the northern half — is already struggling with early-morning darkness.

The researchers went granular, finding that within a single time zone, people living on the western edge — where the sun comes up slightly later than on the eastern edge — sleep nearly an hour less per week. Those on the western edges of time zones ended up with measurably worse moods, lower productivity, and even demonstrably poorer school performance. The American Academy of Sleep Medicine reached the same conclusion in 2023, as have essentially every other sleep and circadian science organization that has weighed in since.

Children, the author argues, will pay the steepest price for this boon to the golf industry that the Senate is on the verge of inflicting at Trump's insistence. Research by the online-schooling company K12 found that under permanent daylight saving time, fully 94 of the largest 100 school districts in the country would have children leaving for school in the dark every single winter morning. The average large district would see 117 dark commutes a year, compared with 77 under the current system and just 35 under permanent standard time. Both options would do away with the clock changes; the difference is whether the daylight lands in winter mornings or in evenings.

The track record is not encouraging. Russia tried permanent daylight time in 2011 and reversed it three years later. Chile tried it in 2015 and reversed it. The United States tried it in 1974 and reversed it as well. The Senate's task now, in effect, is to decide whether to break that pattern or repeat it. Cotton — whatever else one thinks of him — got this one right, the author writes, when he said:

"No one likes changing the clock, me included, but Congress has enacted permanent Daylight Saving Time multiple times before and repealed it each time once Americans experienced absurdly late sunrises in the winter."

Pretty much everyone is tired of the twice-a-year clock changes. Traffic accidents rise in the week following the switch, as the entire country experiences something akin to jet lag. University of Colorado researchers combed through 22 years of federal car accident data and found that traffic fatalities jump about 6 percent in the week after clocks spring forward. A Michigan hospital study found heart attacks up 24 percent on the morning after the spring change. And a study of more than 20 years of injuries in the mining industry found workers got hurt more often and were less productive the day after the change.

There is broad agreement that the twice-a-year jolt to our brains should end. But the author's conclusion is pointed: making daylight saving time permanent, rather than returning to standard time, would enrich Trump and the golf industry by millions while sending the nation's children, workers, and drivers to the hospital — or the graveyard.