Q&A: US ‘should end seasonal clock change’ by adopting permanent standard time

This Sunday, most Americans will adjust their clocks 1 hour to “spring forward” into daylight saving time, at which time they will lose an hour of sleep but gain an hour of daylight.

Shifting our clocks twice a year has been a constant point of contention; in 2022, a bipartisan bill to make daylight saving time permanent was passed in the Senate but remains stalled in the House.

Healio spoke with Karin Johnson, MD, FAAN, FAASM, professor of neurology at UMass Chan School of Medicine-Baystate and a fierce proponent of standard time, to understand the effects of clock changes and the feasibility of a single-time solution.

Healio: What are your objections, scientifically and personally, to the proposed switch to permanent daylight saving time currently stuck in Congress?

Johnson: Most people think the only problem with daylight saving time is the period around the time change, and thus it doesn’t make a difference whether it is ended with permanent DST or standard time.

Research that has mostly come out in the last 5 to 10 years shows that there are consequences that occur the entire time our clocks are set out of alignment with sun time. When sunrises and sunsets are delayed, it increases the risk for poor sleep, heart disease, cancer, depression, suicide and fatal car accidents, and worsens standardized test scores.

We also tried permanent DST twice before — the last time in 1974 — and even though people thought it would be a great idea, it quickly became unpopular because winter sunrises are after 8 a.m. for 2 to 4 months in different locations.

For the economy, places with later sunrises and sunsets are more likely to have people miss work, be later for work, call out for health care problems and be less productive. This is especially the case for anyone with work start times at 8 a.m. or earlier.

I have kids, and teenagers who have a tendency toward sleeping in later are at higher risk from DST, which can affect how they do in school, their likelihood for obesity, their risk-taking behaviors and decision-making. As a sleep doctor, I believe this is the biggest sleep-related public health improvement we can make.

Healio: Were you in favor of the adjustments made in 2006, which reduced standard time from the last Sunday in October to the first Sunday in November and from the first Sunday in April to the second Sunday in March?

Johnson: While we didn’t know as much about the long-term effects in 2006 — and thus didn’t see science push back at the time — given what we know now, the more time we are on DST the worse it is for us.

The greatest harms are in the summer, when the days are longest making it harder for us to fall asleep on time, and especially in the winter when the days are shortest and we lose the most morning light, which is really important for setting our circadian rhythms.

Healio: What would you have changed if consulted on those adjustments?

Johnson: We would have advocated for the least amount of time on DST — and preferably none — so that we can also avoid the short-term harms of the change, which include increased strokes and heart attacks.

Healio: Can any scientist, politician or resident reasonably expect a single time solution for a nation as large as the U.S.?

Johnson: Yes. Sixty percent of the world does not switch clocks, with most on standard time. Arizona, Hawaii and the five U.S. territories are all on standard time.

It will be costly to make the switch and take planning. For example, representatives at United Airlines say they want at least 2 years to test their systems.

We need state bills for standard time. Since we have been actively talking about the problem with permanent DST, no further state bills passed last year and there are fewer co-sponsors of the federal Sunshine Protection Act.

Also, public opinion surveys are very misleading, as many people don’t even know what they are voting for. A lot of misinformation is being spread, especially by politicians, that we would stop the harms of short-term effects of the clock change and don’t account for the long-term harms of being on the wrong time throughout the year.

Overall, the best option would be a federal solution to make a single unified change.

Healio: Based on your sleep research, what solutions do you suggest for adjusting or eliminating the periods of time where Americans live through daylight saving and standard time?

Johnson: We should end seasonal clock change with permanent ST. It would be best if some Western edge states that are in the wrong time zone switch to appropriate time zones, like Indiana or Michigan.