Time Changes Everything — Or Does It?

This weekend marks one of my least favorite rituals: setting our clocks forward an hour as daylight saving time begins. Yes, the evenings will be brighter. The change is quick and routine — but still disruptive. And judging by the collective groan every March, I’m clearly not the only one who feels that way.

Still, twice a year the nation participates in this small act of time travel. Phones adjust automatically, ovens get reset, and after a few groggy mornings many of us wonder why losing just one hour can feel so dramatic. The question inevitably follows: why do we still change the clocks at all?

The Story Behind the Shift
The idea of shifting clocks dates back more than a century. While Benjamin Franklin once joked about making better use of daylight, daylight saving time was adopted during World War I to conserve fuel. In the U.S., it was introduced in 1918, repealed after the war, and eventually standardized by the Uniform Time Act of 1966. The schedule has been tweaked several times since, most recently in 2005, when DST was extended further into March and November.

Globally, the U.S. is unusual — more than 60 percent of countries stay on standard time year-round. Even within the U.S., Arizona (except the Navajo Nation), Hawaii, and several territories opt out.

Daylight saving remains debated: the U.S. Senate passed the Sunshine Protection Act in 2022 to make it permanent, but it stalled in the House.

Bottom line: the clock-change ritual goes on.

Springing Forward Hits Hard
Research suggests that changing our clocks can have measurable effects on health — and “springing forward” tends to be the more disruptive shift.

Research shows that changing our clocks can affect health — and “springing forward” is usually the toughest shift. That lost hour can disrupt our circadian rhythms, the body’s 24-hour cycle that controls sleep, mood, appetite, and other functions and largely depends on light exposure. Less morning light can dampen serotonin, the hormone linked to mood and alertness. At the same time, extra evening light can delay melatonin, the hormone that signals it’s time to sleep.

Many people need several days to adjust — staying up later or waking earlier than usual. One study found the average person loses about 40 minutes of sleep the Monday after daylight saving begins.

In other words, losing an hour can feel like losing far more.

Losing More Than Sleep
But sleep isn’t the only thing slipping away. Measles — declared eliminated in the U.S. in 2000 — is back, fueled by falling vaccination rates and growing skepticism. Already this year, 1,281 cases have been reported, putting the nation on pace to surpass last year’s total of 2,258.

Meanwhile, the scientific infrastructure supporting public health is under strain. Since January 2025, more than 7,800 research grants have been cut or frozen, roughly 25,000 scientists and staff have left federal health agencies, and nearly 80 percent of CDC center directors have resigned or been forced out. Public trust is showing cracks, too: while about two-thirds of Americans say they trust career scientists, confidence in agency leadership is just 43 percent.

Coverage gains under the Affordable Care Act are eroding, leaving more Americans uninsured or underinsured as costs rise and access gaps persist.

Does Time Really Change Everything?
Twice a year we move our clocks and call it change. Daylight saving may be a small disruption, but in public health, the stakes are much higher — coverage, research, and trust can slip away if we don’t act. Time alone won’t protect progress.

A memorable exchange from the television series House captures it perfectly:

“Time changes everything,” one character says.

“It’s what people say,” Dr. Gregory House replies. “Doing things changes things. Not doing things leaves things exactly as they were.”

The lesson is clear: time itself rarely solves problems. What we choose to do with it does.

Happy reading,
Suzanne Daniels, Ph.D.