Did Daylight Saving Time Happen This Year? A Look at the Switch and Beyond

Across much of the United States and Canada, Daylight Saving Time (DST) began on Sunday, March 10, 2024, at 2:00 a.m. local time. As is tradition, most people sprung their clocks forward an hour, effectively trading an hour of morning sunlight for extended daylight in the evenings. This practice, which ends in the fall when clocks are turned back, aims to better align our waking hours with natural daylight. However, a significant shift is underway, with British Columbia leading the charge towards a permanent change.

British Columbia Says Goodbye to the Switch

British Columbia recently made the decision to abolish the twice-yearly clock changes, ushering in an era of permanent Daylight Saving Time. According to Premier David Eby, the move was overwhelmingly supported by residents – with over 90% in favor. “The way that we live our lives now in the modern era, having an extra hour of sunlight at the end of the day, whether it’s the winter or the summer, makes a big difference for people,” Eby explained to NPR’s Adrian Ma on All Things Considered.

The Debate: Health Concerns and Circadian Rhythms

While popular with many, the change isn’t without its critics. Experts in sleep medicine and public health express concerns about the negative effects of altering our natural rhythms. Emily Manoogian, a senior staff scientist at the Salk Institute and an executive member of the Center for Circadian Biology at University of California, San Diego, highlights the downsides. “Daylight saving time has been shown to have a lot of negative effects,” she states. In fact, the United States briefly experimented with permanent DST in the 1970s, but quickly reverted due to widespread issues.

During that period, people experienced difficulties functioning in the dark during morning commutes, and tragically, there was an increase in fatal car accidents. Premier Eby acknowledges these health risks but points out that British Columbia residents are already accustomed to dark winter mornings due to the province’s western location.

Why Our Biology Prefers Standard Time

Manoogian explains that our internal circadian clocks – which govern not only our sleep-wake cycles but also crucial bodily functions like cardiac and metabolic processes – are fundamentally synchronized with daylight. “Light is the largest cue to coordinate behavior,” she says. When we wake up and are exposed to sunlight, it signals our brains to activate the body for the day. Without this morning light, our bodies struggle to adjust, leading to a cascade of potential problems.

Conversely, bright evenings can make it harder to fall asleep, creating a cycle of disrupted sleep and impaired daytime functioning. This disruption can have far-reaching public health consequences, including increased risks of car accidents, heart attacks, and strokes in the week following the DST shift. Manoogian emphasizes that “sleeping, eating, getting light at the wrong time is a huge risk for cardiometabolic disease.”

The Evidence: Studies on Time Changes and Health

Research supports these concerns. A study by Stanford researchers published in the Proceedings of the National Academy of Sciences found that switching clocks twice a year significantly impacts public health, contributing to increased strokes and obesity rates. The study indicated that a permanent switch to standard time could prevent 300,000 strokes and over 2 million cases of obesity annually.

While permanent DST also showed some benefits, the study found that permanent standard time offered greater health advantages. As Manoogian succinctly puts it, “the health benefits of standard time are pretty great.”

Mitigating the Effects of Daylight Saving Time

If you’re concerned about the impact of DST on your health, Manoogian suggests taking steps to ease the transition for your body. (Further tips can be found on NPR’s website)