Each spring, we lose an hour of sleep. Each autumn, we gain it back. But what really happens to our health when the clocks change, and is it time for a change?
British Summer Time (BST) was introduced in 1916 during the First World War as an energy-saving measure. The idea was simple: make better use of daylight, conserve fuel and support the war effort.
More than a century later, we’re still shifting the clocks twice a year. But while lighter evenings are widely welcomed, growing research suggests the clock changes may have real health consequences.
Why do we change the clocks in the first place?
BST was originally designed to reduce energy use. Today, the argument centres more around lifestyle and economic benefits.
Longer evenings can:
- Encourage outdoor activity
- Support retail and hospitality
- Boost tourism and sport
However, modern studies suggest energy savings are now minimal, and may even be offset by increased use of heating in darker mornings or air conditioning in lighter evenings.
So if the original rationale is weaker, attention naturally turns to the health impact.
Is our health affected by the clocks changing?
This is where the debate intensifies.
The spring transition (when we lose an hour) has been linked to:
- A short-term rise in heart attacks
- Increased stroke risk
- Sleep disruption
- Low mood and irritability
Even a one-hour shift can disrupt our circadian rhythm, the body’s internal clock that regulates sleep, hormones and metabolism.
Sleep researchers increasingly argue that repeated clock changes place unnecessary strain on this system. Some even suggest that if we were to abolish the seasonal shifts, permanent standard (winter) time would be healthiest, as it better aligns with natural light patterns.
Why some countries have scrapped daylight saving time
While we call it British Summer Time, it’s known as Daylight Saving Time in the US, and not all countries observe it.
Nations closer to the equator, where daylight hours remain consistent year-round, see little need. Others, including Japan and Russia, have abandoned the practice.
In 2018, the EU proposed ending seasonal clock changes after 84% of 4.6 million respondents voted to scrap them. However, disagreements between member states stalled the proposal.
For now, the twice-yearly ritual continues.
Who really benefits?
Contrary to popular belief, farmers were not behind the introduction of BST. Many actually opposed it.
In the US, extensions to Daylight Saving Time have reportedly been influenced by lobbying from industries including golf, barbecues and confectionery, even stretching the lighter evenings to encompass Halloween’s trick-or-treating.
Which leaves us with a fair question: are we prioritising convenience over wellbeing?
So, should we stop changing the clocks?
There’s no denying that lighter evenings feel uplifting. They signal spring, sociability and seasonal renewal.
But as awareness grows around sleep, circadian health and metabolic resilience, the health impact of clock changes is receiving renewed scrutiny.
If shifting the clocks no longer meaningfully saves energy (and may carry measurable health costs) it may be time to reconsider whether the tradition still makes sense.
