As B.C. prepares for what could be its last ever time change this weekend, one expert is raising concerns about the health implications of adopting a permanent daylight saving time (DST).
“I think it’s fine to switch to standard time and do away with the annual switches. But switching to daylight savings time, it’s not the right choice, and that’s the consensus of pretty much all of the experts,” said Ralph Mistlberger, a psychology professor at Simon Fraser University who researches the functions of circadian rhythms and sleep.
Morning light is important for setting people’s circadian rhythm, or biological clock, which gets on the day-night cycle from our eyes.
Most humans’ clocks run at about 24.2 hours (that’s how long it takes for our clocks to complete a cycle). But it stays synchronized to the solar day (24 hours) when we expose ourselves to morning light.
Evening light, however, has the opposite effect.
“If you take away morning light and add it on to the evening, then the net result is that the clock, your biological clock, will naturally synchronize with the light-dark cycle, but it’s synchronized at a slightly later phase, so it makes it harder to get up early.”
Mistlberger is concerned about the effects of this in the winter months when days are short and we will be missing an additional hour of light in the morning.
Most people will be battling “social jet lag,” or a misalignment between the circadian clock and social clock (which is what we use our watches to keep track of and is when we start work, school, and so forth).
When people are misaligned, it is harder to go to both wake up early in the morning and go to bed at night, which will result in less sleep.
He’s particularly concerned about teenagers, who already have a delayed circadian clock and naturally tend to stay up later. He said sleep experts have already been encouraging school boards to start school later, to align with teens’ natural clocks.
The permanent change to DST could cause teens to lose out on even more sleep and influence how well they do in high school. Someone who is chronically sleep deprived is less likely to make good decisions and resist impulses.
Mistlberger also noted that there are a number of chronic health problems, like cardiovascular disease and obesity, that are higher in DST than in standard time.
What’s the best option?
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The twice-annual time changes weren’t ideal, either.
When Premier David Eby made the announcement on Monday, March 2, he said the move would improve health, reduce disruptions for families, and allow for an extra hour of light during winter evenings.
“Every parent knows that changing clocks twice a year causes a significant amount of chaos on already busy lives,” he said. “British Columbians have been clear that seasonal time changes do not work for them.
“This decision isn’t just about clocks. It’s about making life easier for families, reducing disruptions for businesses and supporting a stable, thriving economy. I am hopeful that our American neighbours will soon join us in ending disruptive time changes.”
Many B.C. residents responded to a 2019 survey, stating they wanted to switch to daylight saving time year-round.
“In 2019, more than 93 per cent of a record 223,000 British Columbians told us they wanted to remain on year-round daylight-saving time (DST),” the B.C. Ministry of the Attorney General told Daily Hive in 2023. ‘It is as clear a message as we could hope to receive. British Columbians told us that it’s important to maintain alignment with our neighbours in Washington, Oregon, and California.”
Mistlberger thinks the government decided this because most people want more light in the evening.
“That’s true. We do,” he said.
But he added that most people might not be aware of circadian biology or understand the effects of losing morning light.
“It’s important that the politicians listen very carefully to what the actual experts are saying. And not everybody who speaks up is an expert.”
Rather than permanently going to DST, Mistlberger and organizations like the Canadian Sleep Society advise switching over to Standard Time.
Standard Time was created so that time zones aligned with the day-night cycle, so that the sun is directly overhead at noon.
“And that, biologically, seems to work the best for the most people,” said Mistlberger.
How to prepare?
Clocks move ahead one hour early Sunday, March 8, meaning that we are losing an hour of sleep this weekend.
To prepare, Mistlberger recommends going to bed earlier than normal.
“It’s a good weekend to not stay up late,” he said.
On Sunday and Monday, he advises people to go out early and get sunlight early in the morning, which will help shift their circadian clock.
When it comes to the winter months and we have an hour less of daylight in the morning, Mistlberger recommends getting a light therapy lamp (often sold at pharmacies), which has a much higher level of light output than normal lights, and turning it on in the morning.
Inthe evenings, he said it’s a good idea to minimize light exposure, since artificial light can delay your circadian clock.
“Your clock thinks that the sun is still up. It’s responding to all of the ambient light.”
This, in turn, suppresses melatonin secretion from the pineal gland, which starts to occur in the evening prior to when we go to sleep.
“That’s just basic biology,” Mistlberger said. “Daylight Saving Time is working against our best interest as far as regulating our daily rhythms, which are so important for determining how easy it is to sleep, and how likely it is that we’re going to get the amount of sleep which is optimal.”
With files from Daniel Chai