Daylight saving time should be permanently abolished in the United States

What's this about?

People disagree about whether the United States should stop changing its clocks twice each year.

The best answer may be to end the changes, while choosing a new clock plan remains unclear.

What supporters say

• Clock changes can cause lost sleep, more crashes, work harm, and health trouble, so ending them could remove these risks.
• Keeping normal time all year may fit the body’s sleep clock better than keeping summer time all year.
• Clock changes may not save power, and they might even raise home power use in some places.

What critics say

• More light in the evening could help people spend time outside and help some shops and groups.
• Summer time all year could make winter mornings much darker for people going to school or work.

How to read this

The number of points on each side does not show who is right; the strength of the proof matters more.

The bottom line

The proof clearly supports ending the clock changes, but it does not clearly choose normal time or summer time all year.

The case against clock changes is stronger than the case for one exact replacement.

The United States should end its twice-yearly clock changes, but the evidence does not clearly show whether the country should adopt permanent standard time or permanent daylight time. The strongest case is against the clock shifts themselves, not necessarily for every possible replacement.

The case for

The clearest argument for abolition is that changing the clocks creates recurring disruption. Research reviews have linked the spring and autumn transitions with sleep loss, accidents, mental-health effects and cardiovascular problems. Another analysis found a possible short-term increase in heart-attack risk around the changes. The studies vary in quality and results, so the size of the harm remains uncertain, but they consistently suggest that the transitions themselves carry real costs. 1

A separate peer-reviewed study found that people slept less and workplace injuries increased after the spring change. That does not prove that either permanent time system would be better in every respect, but it strengthens the case that eliminating the twice-yearly shifts would remove at least some repeated risks. 1

The traditional argument that daylight saving time saves energy is also weaker than it once appeared. A study of Indiana’s adoption of daylight saving time found no overall reduction in household electricity use, and possibly an increase. The result may not apply equally to every state, since climate, technology and household habits differ. Still, it challenges the idea that changing the clocks provides a reliable national energy benefit. 2

If the country chooses permanent standard time, sleep experts offer an additional argument. The British Sleep Society and a policy analysis say standard time generally fits the body’s natural sleep-and-wake rhythm better than permanent daylight time. This is expert guidance and policy analysis, rather than a direct U.S. experiment comparing the two systems, but it supports permanent standard time as the more biologically cautious choice. 3 (see Figure 2)

The case against

Ending seasonal changes would not settle the harder question of which time should last all year. Permanent daylight time would provide more light in the evening, but it would also make winter mornings darker. Modeling suggests substantially more dark morning commutes to school for children, especially in northern and western states. That could create safety and fairness concerns, although the estimate comes from a recent preprint and depends on assumptions about school schedules and travel. 4

Later evening light may also have social and economic advantages. It could encourage leisure, shopping and other activity after work or school. But those findings come from economic models, not direct evidence showing that permanent daylight time would improve national well-being more than the alternatives. 5

A permanent system could simplify schedules for households and businesses, yet changing the rules would still affect aviation, transportation, broadcasting, software and interstate commerce. Time changes already influence operational coordination in aviation, while the broader national cost of changing the system has not been well measured.

The bottom line

The evidence favors abolishing the clock changes, but only moderately favors the broader claim as worded. Confidence is high that the seasonal transitions cause recurring sleep and safety problems, and the energy case for them is weak. Those are the strongest findings.

The evidence is much less decisive when comparing permanent standard time with permanent daylight time. Permanent standard time fits sleep-medicine guidance better and avoids the clearest concern about dark winter mornings. Permanent daylight time offers more evening light, but brings greater modeled risks for morning school commutes. Neither system has been directly compared across the United States over health, safety, economic activity, fairness and operational coordination.

The most defensible policy is therefore permanent standard time, with careful planning for schools, transport, commerce and coordination across states. The evidence does not support treating permanent daylight time as an equally safe or risk-free replacement.