US house passes permanent daylight saving time bill; senate passage

The US House of Representatives has passed a bill to make daylight saving time permanent year-round, though it is unlikely to pass the Senate. The move has renewed debate about how we measure time and who decides. The United States tried permanent daylight saving time in the 1970s.

It proved unpopular and was abandoned. Individual US states can already choose whether to observe daylight saving time, but a federal change would apply across the country. Time is not natural – it is decided Elizabeth Cohen, a political science professor at Boston University who has studied how humans track and use time, is direct: "Every measurement of time is arbitrary. Every deadline could have been a fraction of a second or a large increment of time different than it was. None of it is natural."

Michael O'Malley, a professor of history at George Mason University, agrees that daylight saving time reflects a "desire for natural time" – the wish to align clocks with the sun – but adds: it "only makes sense in a society that's completely hypnotized by clocks so you think the clock is time." Before the Industrial Revolution, which began in 18th-century England, timekeeping was different.

Kevin Birth, a professor of anthropology at Queens College, describes pre-industrial systems as ones "that tended to expand and contract based on the time of year and the location." People followed the sun, not a fixed schedule. Industrialisation changed that.

Factories needed workers to arrive and leave at set times. As O'Malley puts it: "It was one of the goals of industrialization to instil in people this regular, unvarying sense of time." How railroads built the modern clock By the mid-1800s the United States had more than 40 city-based time zones, creating chaos for railroad companies whose trains crossed between them.

In 1883 the American Railway Association took matters into its own hands. O'Malley explains: "The American Railway Association got all the American railroads to agree that on Nov. 18, 1883, they would declare a four-zone system in effect in America. And they just announced it."

No government vote. No public consultation. The railroads decided and it stuck.

The following year, an international conference selected Greenwich, in England, as the basis for global timekeeping and navigation – the Prime Meridian. Birth says the choice reflected British imperial power at the time, not geography or science. Politics shapes the clock China stretches more than 5,000 kilometres across Asia, a distance that would naturally span several time zones.

Yet the country runs on a single official time – Beijing time – introduced after the Communist Party took power in 1949 as a statement of national unity. In the far west, people quietly adjust their daily routines to local solar time because the sun rises hours later there than on the eastern coast. The Gregorian calendar – with its 12 months and leap years – is the most widely used in the world, but not universal.

Countries including Israel and Thailand use other calendars for religious or cultural purposes alongside it. Cohen argues that control over time is a form of political power. Governments impose curfews; workers use slowdowns and strikes to push back.

"Time has a lot of power," she says, "and people are battling over it to try and impose themselves on others or remove the yoke that has been imposed on them." Birth is equally plain: time zones "are about politics." The debate over daylight saving time is, in that sense, nothing new.