America already tried permanent daylight saving time

It lasted ten months.

The Sunshine Protection Act is often described as an untested idea. It isn't. The United States adopted year-round daylight saving time in 1974 — and repealed it before the year was out. What happened then is the best available evidence for what would happen now.

Why it happened

The trigger was the 1973 oil embargo. With energy prices spiking, Congress passed the Emergency Daylight Saving Time Energy Conservation Act, betting that shifting an hour of daylight into the evening would cut electricity demand. President Nixon signed it in December 1973, and on January 6, 1974 the country moved its clocks forward and simply left them there.

Support beforehand was broad. Polling at the time showed most Americans in favor. The idea was popular in the abstract — much as it polls well today.

What went wrong

The problem arrived immediately, and it arrived in the morning. January sunrises are late to begin with; adding an hour pushed them past 8 AM across much of the country, and past 9 AM in the western edges of time zones. Children who had previously walked to school in daylight were now waiting for buses in the dark.

Several children were struck by cars in the winter mornings that followed. Whether the time change caused those deaths was disputed then and is still disputed by researchers now — but the public did not wait for the studies. Dark-morning school runs became the defining image of the experiment, and support collapsed. By the spring, polling had roughly inverted.

How it ended

In October 1974 Congress amended the law to restore standard time for the winter months, and the experiment was allowed to expire in 1975. The country returned to the twice-a-year switch, which is where it has stayed ever since.

What it means for the bill in front of Congress today

The Sunshine Protection Act would do the same thing the 1974 law did: stop the clocks from falling back. The daylight math is identical — the sun's behavior hasn't changed. Winter mornings would again be an hour darker and winter evenings an hour lighter.

What has changed is the country around it. Far fewer children walk to school. Work is less synchronized to sunrise. Whether that makes the trade-off more tolerable now is exactly the question the Senate would be deciding, and reasonable people land on both sides of it.

The honest summary is that 1974 doesn't prove permanent daylight time is unworkable. It proves that the winter mornings are the part people notice — and that support measured in summer is not the same as support measured in January.

This page describes the Emergency Daylight Saving Time Energy Conservation Act of 1973 and its 1974 amendment. The Sunshine Protection Act has passed the House only — it is not law.