The hidden cost of permanent daylight saving time

An hour may seem trivial, but in Washington it has triggered a significant political debate. The US leader is advocating for the Sunshine Protection Act, which aims to implement daylight saving time throughout the year, thus ending the ritual of adjusting clocks twice a year.

Supporters of the move see an obvious benefit: no more fiddling with clocks, more daylight after work and, perhaps, more time for shopping, dining and recreation.

It is an appealing proposition, but also an incomplete one.

The fundamental question is not whether US citizens would like an extra hour of evening light, but who benefits from that hour and who bears the cost.

Daylight saving time was not designed as a permanent fixture. Germany introduced it during World War I as an emergency measure to conserve fuel and electricity. Other nations soon followed.

The logic was straightforward: shift an hour of daylight from the morning, when many people are asleep or beginning their day, to the evening, when they are more likely to need artificial light.

After the war ended, the clocks moved back. The idea returned during World War II and persisted in some countries long after the emergency that created it had passed.

This history matters because daylight saving time is fundamentally a bargain with geography. It makes more sense at higher latitudes, where there is a significant difference between summer and winter daylight. Near the equator, the gains are minimal.

In a country as vast as the US, the same hour holds different meanings across regions.

Consider the consequences when Washington moves the clock forward, and labels it a national solution. In Florida, a later sunset in winter would mean an extra hour for restaurants, retailers, golf courses and tourist attractions.

But in the northern parts of the country, that same hour gets deducted from the morning. The sun rises later, leaving children waiting for school buses in darkness and workers commuting before daylight.

The US previously tried this experiment during the 1973-74 oil crisis, when President Richard Nixon enacted a law putting the country on year-round daylight saving time, partly to reduce energy consumption. Public enthusiasm initially ran high, but quickly waned due to concerns about dark winter mornings, particularly for school children.

The experiment was abandoned well before its intended conclusion, serving as an important reminder that a seemingly simple national policy can have very different implications depending on the location.

This encapsulates the problem with the politics of the clock: there is no national sunrise. But there are substantial economic interests on both sides of the argument.

Retailers, restaurants, bars and leisure businesses naturally favor more daylight after working hours, because an extra hour of sunshine encourages people to spend time and money outside their homes, benefiting a consumption-driven economy.

At the same time, technology and financial companies support a fixed clock because it eliminates the technical challenges of biannual changes in trading systems, databases, scheduling software and global operations.

However, some of the costs are not easily quantified on a balance sheet. Sleep specialists have long argued that if seasonal clock changes are eliminated, permanent standard time is preferable to permanent daylight saving time, as morning light is crucial for regulating the body's circadian rhythm.

The American Academy of Sleep Medicine, for example, has called for year-round standard time rather than year-round daylight saving time.

This distinction is crucial. The issue is not merely the inconvenience of adjusting clocks twice a year, but also whether convenience should come from permanently moving social schedules away from the sun.

Farmers face a different problem altogether. Livestock and crops do not adhere to clocks or congressional mandates. Agriculture relies on daylight, weather and biological cycles, irrespective of whether Washington decrees that 7 am should be treated as 8 am.

None of this implies that permanent daylight saving time is inherently flawed. Rather, it underscores its political aspects.

Every time policymakers adjust the clock, they redistribute a resource that cannot be manufactured: daylight. Some get more of it at the end of the day; others get less at the beginning. One industry gets a longer window for consumption; another must adapt to the adjustment. Some commuters gain brighter evenings. Others lose brighter mornings.

Therefore, the debate should not be reduced to whether US citizens are tired of adjusting their clocks. They are, but the more important question is what kind of society they want their clocks to serve.

Permanent daylight saving time may indeed spare millions of people the twice-yearly ritual of resetting their clocks. But it cannot alter geography, human biology or the sun. An hour gained by one part of the US is an hour taken somewhere else.

The clock may be set, but the debate over who pays for the hour will continue.

The author is a professor of the Maritime Silk Road Institute, Huaqiao University.

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