Daylight time may not be worth the switch

[CBC News]

It’s time to spring forward: daylight time takes place in most of Canada at 2 a.m. on March 13. But not every part of the country is on board, and some researchers argue that DT does us more harm than good.

In studying the pros and cons of switching to and from daylight time, University of British Columbia economist Werner Antweiler found very little evidence of benefits — but notable research showing the downsides of the practice.

“The benefits didn’t show up, and in fact where people looked at it closely they found the opposite,” Antweiler tells Yahoo Canada News. “On the other hand, when people looked at the costs, they are very measurable.”

Daylight time was first proposed in 1784, by U.S. inventor and politician Benjamin Franklin. Most areas of Canada and the United States adopted DT in 1966, and it’s now followed in about 70 other countries around the world.

Initially clocks moved forward an hour on the last Sunday of April, and back again the last Sunday of October. But in 2007 clocks in North America instead began changing on the second Sunday in March and the first Sunday in November.

But the experiences of those areas that either never have instituted DT, or adopted it more recently, have provided some evidence of the concept’s potential downsides.

For example, a decade ago Indiana converted to DT, and one study found that energy demand increased slightly post-shift, countering the idea that DT reduces energy use. There were energy savings related to lighting use, the study found, but those were negated by increased use of air conditioning in summer evenings and heating on fall mornings.

Heart attacks, car accidents and other DT downsides

Other researchers have found that the shift to DT results in productivity losses, and sleep experts have said that it affects our rest. One study by another UBC researcher, Maurice Levi, found that switching to DT increased usual dips in the stock markets seen on Mondays. A 2014 study found that hospital admissions for heart attacks increased 25 per cent in Michigan on the Monday after clocks sprung forward. And past research has indicated that we’re likely to see an increase in car accidents this coming Monday, Antweiler says, as a result of the shift to DT.

“These are numbers that are problematic,” Antweiler says, “even if only a very small popular of the population is affected.”

Even if the effects of DT — for example, the increased risk of car accidents — only affect a small percentage of the population, he says, the effects add up when they concern the entire populations of Canada and the U.S.

Some parts of Canada don’t make the switch to DT, including most of Saskatchewan, Quebec east of 63° west longitude, some northwestern Ontario towns, parts of northeastern B.C. and Nunavut’s Southampton Island. But it’s hard to compare those areas to others that do follow DT in order to see what might happen if the country as a whole stopped making the switch, Antweiler says.

“You kind of need an experiment where you’re forcing the same people to switch, rather than comparing people in different places,” Antweiler says. That’s why examples like Indiana are so valuable.

And it’s important to remember that the problem isn’t with daylight time itself — it’s the switching back and forth, and the resulting effects on sleep and productivity, that are the issue, Antweiler says. Any move away from switching to and from DT could involve either staying permanently on standard time, or switching to DT and just never switching back.

The latter option may be the best one, Antweiler says. A British study found that permanently moving to daylight time may be the best fit for society’s usual waking and sleeping hours.

“By making a few subtle adjustments, they found in a stimulation study that if there are energy savings to be had, it’s from year-round DT,” he says.

And given that the research is heavier on the downsides of DT than the benefits, and that many Canadians complain about switching clocks twice a year, why do we continue to do it?

“We’ve been doing it so long that we kind of forget why we’re doing it,” Antweiler says.

And as long as the United States continues to switch to and from DT, Canadian is likely to do the same as evidenced by how quickly we got on board when the U.S. shifted the dates back in 2007, he says.

But in parts of Canada and the U.S., there is some momentum to do away with DT. One man in Kamloops, B.C., launched an online petition to end the twice-yearly clock changing in his province, for example. South Dakota is considering a bill that would end daylight time, and several other U.S. states have had similar debates.

“I think we have to keep a close eye on what’s happening in the U.S. and maybe we should have this discussion too,” Antweiler says. “Quite clearly, if you look at a cost-benefit analysis it’s not holding up.”