Donald Trump wants the United States to stop changing the clocks twice a year. But the president’s solution—permanent daylight saving time—goes against the recommendations of several sleep researchers. There are also demands in Sweden to end daylight saving time, but the issue is stuck at the EU level.

The debate about daylight saving time has flared up again in the US. In recent days, President Donald Trump has urged the Senate to approve a bill that would make daylight saving time permanent, thereby stopping the recurring switch between summer and standard time.

Trump has described the time change as both inconvenient and costly. He also claims that ending the clock changes could result in longer light evenings, help reduce crime and traffic accidents, and benefit commerce, restaurants, tourism, and leisure activities. Trump has also referred to possible positive effects on health.

The US House of Representatives voted in July for a bill to make daylight saving time permanent. If the law passes the Senate, the US would no longer move the clocks back in the fall. However, the proposal has faced opposition, including from states and interest groups worried about dark winter mornings.

Introduced Under Different Circumstances

Daylight saving time was originally implemented to make better use of daylight. The idea was to shift an hour of daylight from early morning to the evening when more people are awake and active.

The system gained traction during World War I when several European countries introduced daylight saving time to reduce the need for artificial lighting and thus save energy. Time changes were also used in many places during World War II.

Since then, energy systems and people’s lifestyles have changed dramatically. As a result, the original argument about energy savings is much more debated today. The modern debate is instead largely about what happens to the human biological clock when society’s time is suddenly shifted by an hour.

Researchers Don’t Necessarily Support Trump’s Model

Here comes an important distinction between the political and the medical debates. There is support for the idea that the change itself can disrupt sleep and circadian rhythms. The American Academy of Sleep Medicine has therefore long advocated for abolishing the time change. But the organization also advocates for permanent standard time, not permanent daylight saving time.

The argument is that standard time better aligns with the human body’s natural circadian rhythm. When the clocks are set forward an hour in the spring, people effectively get less morning light and more light in the evening.

At the same time, research is not completely clear regarding all the health risks sometimes connected to time changes. For example, studies have looked at links to cardiovascular disease, stroke, traffic accidents, and mental health issues, but the results vary between studies.

One previously published study, for example, found no clear link between the switch to daylight saving time and suicide, although the researchers noted that the results are mixed and that more research is needed.

However, a modeling study from Stanford indicated that a permanent time system could provide better health outcomes than the current system. The researchers found that both permanent standard time and permanent daylight saving time would be better than continuing to switch twice a year—but permanent standard time offered the greatest estimated health benefits.

This means that Trump’s core argument—that it’s better to stop changing the clocks—has some support from research. But researchers often reach a different conclusion than the president: abolish the time change, but keep standard time.

The US Has Already Tried Permanent Daylight Saving Time

There is also a historical precedent that is relevant to today’s American debate. During the energy crisis in the 1970s, the US introduced permanent daylight saving time in an attempt to save energy. However, the change quickly became unpopular. In particular, the dark winter mornings drew criticism when children went to school and people to work.

The experiment was abolished after only about a year.

This historical experiment is now used by opponents of Trump’s proposal as an argument that the country should not repeat the same mistake. Proponents instead highlight the benefits of longer light evenings, something that, among other things, can benefit commerce, restaurants, and leisure activities.

Sweden Also Has Politicians Who Want to Abolish Daylight Saving Time

Sweden faces the same fundamental issue as the US, even though the decision is practically more complicated since the time change is regulated within the EU.

In Sweden, the issue has repeatedly come up in parliament. Sweden Democrat Markus Wiechel, during the 2025/26 session, submitted a motion demanding that daylight saving time be abolished.

Wiechel cited, among other things, sleep problems, fatigue, difficulty concentrating, and potential health risks. He also argued that the original argument about energy savings is no longer strong enough to justify the time change. The motion was considered by parliament but was rejected.

There is thus also political support in Sweden to end the system. But that does not necessarily mean that supporters want daylight saving time year-round. On the contrary, it is mainly permanent standard time that aligns best with the position put forward by sleep researchers.

The EU Is Stuck on the Issue

The European Commission proposed as early as 2018 that the mandatory time change should be abolished. The European Parliament later supported the proposal. Since then, the issue has, in practice, stalled.

The problem is what should replace the current system. If member states are allowed to choose between permanent daylight saving time and permanent standard time, there is a risk that neighboring countries end up in different time zones. This could create new problems for transport, trade, and the European single market.

This is why the EU still uses today’s system, in which member states turn their clocks forward in spring and back in autumn.

Three Alternatives Stand Against Each Other

The political debate can therefore be summarized with three options. The first is to keep the current system, with daylight saving time during the summer months and standard time during the winter months.

The second is to abolish the time change and maintain standard time year-round. This is the model preferred by several sleep medicine organizations, as it is considered to be closest to the human natural circadian rhythm.

The third is permanent daylight saving time, which is the model Trump is now promoting in the US. It gives lighter evenings but also much darker winter mornings.

The American debate, therefore, is really no longer about whether or not to change the clocks. It is about which time the society should follow once the clock changes have stopped.

For Trump, the answer is daylight saving time. For many sleep researchers, the answer is standard time. And in Europe, politicians have yet to reach an agreement on which of the alternatives should apply.

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