When is Daylight Savings 2024? The reason behind the US clock change, explained | BBC Science Focus Magazine

Thanks to Daylight Saving Time, the United States will join the other members of the exclusive clocks changing club by moving back an hour. While it’s goodbye to the long summer nights, it means cosy winter evenings and the holiday season are just around the corner.

In the US, the clocks go back at 2am on Sunday 3 November 2024, marking the end of Daylight Saving Time (DST) and the move to Standard Time.

Here’s a brief lowdown of what the time jump will look like in some of the major cities:

American states follow six main time zones, but when you include inhabited territories, the number jumps to nine. But this is still a huge improvement from the whopping 144 local time zones the country had before many were combined in 1883.

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While the story involves Daylight Saving enthusiasts from opposite sides of the globe, the United States doesn’t enter until Act Two.

In 1895, New Zealand scientist George Hudson suggested the concept of Daylight Saving. By shifting the clocks forward two hours in spring, he hoped the extra light would help him catch more insects. But even for the non-bug lovers, he argued they could use the extra sunlight to get outdoors.

William Willett (ancestor of Coldplay’s Chris Martin, trivia fans) renewed the fight over 10 years later on the other side of the world. The UK builder believed using standard time all year wasted daylight. He wanted to introduce Daylight Time so everyone could lap up more of the summer sunshine.

But it was not until 1916 that the UK thought DST was a pretty good solution for another problem: energy consumption in the First World War.

Which is where the United States comes in. The US has had a bit of an on-again, off-again relationship with changing clocks. It first trialled Daylight Saving in 1918, after much of Europe had introduced it. While other countries had talked the talk about potentially changing their clocks for decades, Germany was the first to do so in 1916.

The United States trialled it in World War I but abandoned it after backlash, especially from farmers who were concerned about changes to their work schedule. It was trialled again in World War II, after which the government standardised it in 1966.

There are quite a few reasons critics oppose changing the clocks. For one, some people find the clocks going forward in March quite disruptive on their bodies. Even though you may lose only an hour of sleep, scientists noticed there was a significant jump in the risk of heart attack in the weeks after the 2019 spring clock change.

It can also harm the economy. In the United States, a researcher estimated the spring time change cost the country $275 million (£225m) every year due to a dip in productivity when clocks go forward.

The shift can also create issues for your furry friends. Pet charities encourage you to adjust your pets slowly to a new routine – if you don’t, they may wake you early thinking you forgot to feed them.

Yes, two don’t. Well almost two. While the majority of Arizona doesn’t subscribe to Daylight Saving Time, a small part does.

Most of Arizona stopped using DST in 1967 because the amount of Sun and heat already makes it hard to cool homes all day.

This creates a problem for the Navajo Nation – a semi-autonomous Native American territory – that exists inside Arizona. It chooses to follow DST, pushing it to Mountain Daylight Time during summer.

If that’s not complicated enough, the Navajo Nation borders a separate semi-autonomous Native American territory, the Hopi Reservation, which chooses not to follow DST like Arizona. So if you drive through those areas in the summer, expect the time to change twice in a matter of hours.

Hawaii also doesn’t follow DST. As it’s close to the equator, the sunlight is pretty consistent year-round, so there’s no need to change the clocks to optimise daylight time.

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