As the US government wants to change the clock ‘forever’, researchers in Canada warn; call it a ‘time bomb’ for …

A renewed political drive in the United States to end seasonal clock adjustments by locking in year-round Daylight Saving Time is facing resistance from both Capitol Hill and the medical community. While President Donald Trump has put heavy pressure on lawmakers to pass the measure — calling for extra evening sunshine for recreation and business — a growing body of scientific evidence warns that the policy could trigger chronic public health damage. Incidentally, some members of Congress in the US have long been interested in the potential benefits and costs of daylight saving time since it was first adopted as a wartime measure in 1942. The Senate passed a bill in 2022 to make daylight saving time permanent, but it got stalled in the House.The debate reignited this week with the publication of a research review in the Canadian Medical Association Journal. As several Canadian jurisdictions weigh ending their own clock changes, researchers examined the physiological fallout of permanent daylight saving time compared to permanent standard time. Their findings endorse permanent standard time as the healthier option, cautioning that extended evening light paired with darker winter mornings runs counter to the fundamental biology of the human body. For those unaware, Daylight saving time is that period between spring and fall when clocks in most parts of the US are set one hour ahead of standard time.

Why researchers are against ‘changing’ the clock

According to the authors of the research report, the human circadian rhythm runs on a natural cycle of roughly 24.2 hours and relies critically on natural morning sunlight to reset and synchronize essential bodily functions. While later daylight hours may accommodate evening commutes and outdoor leisure, delayed sunrise suppresses natural wakefulness. Conversely, lingering evening light delays the internal clock, disrupting sleep quality, mood, and daily productivity.The consequences of late-shifted sunlight are already visible along the geographic borders of current time zones, where sunrise and sunset can vary by over an hour within a single zone. The Canadian review cited evidence showing that Americans living on the western edges of time zones — where the sun sets later — lose roughly an hour of sleep each week compared to those on the eastern side. The researchers concluded that while abolishing biannual clock adjustments eliminates a few weeks of acute disruption each year, the consequences of permanent daylight saving time would be chronic. Their recommendation aligns with broad consensus across international chronobiology and sleep medicine organizations, including a 2024 guidance from British sleep specialists advocating a permanent lock on Greenwich Mean Time.

Permanent daylight bill: Where it stands right now

Called the Sunshine Protection Act, it passed in the House in July this year, but faces roadblocks in the Senate, where some Republicans are strongly opposed to it. Proponents, including President Trump and his administration, argue that the change would provide more daylight during the times that Americans are most active. Those against, say that permanent daylight saving time would lead to darker and potentially more hazardous winter mornings.Despite these warnings, legislative momentum in Washington remains contentious. While the U.S. House of Representatives has advanced a measure establishing permanent daylight saving time, the bill has stalled in the Senate. The impasse even prompted President Trump to escalate public pressure, going so far as to post the personal mobile phone number of Senator Tom Cotton of Arkansas on social media.Defending his stance, Cotton noted that previous attempts to lock the clock to summer hours collapsed once citizens faced the reality of dark winter mornings. Historical records support the pushback: the United States previously adopted permanent daylight saving time during World War II and again during the 1973 energy crisis, with Congress repealing the 1970s initiative after less than a year amid intense public outcry over morning darkness. Similar nationwide trials in Russia and Chile were also later reversed due to public dissatisfaction, safety concerns, and body-clock disruption.Canadian researchers further note that a permanent shift by the United States would place severe economic pressure on Canada to follow suit, regardless of medical advice.