Researchers suggest that changing clocks may impact nation’s health

Researchers have urged the government to eliminate the biannual clock changes in the UK, as they have been found to disrupt sleep patterns and impact overall health and well-being. This advice comes as the nation gets ready for the yearly “extra hour in bed” event this Sunday.

Members of the British Sleep Society emphasized that exposure to natural sunlight in the morning positively affects sleep, while the act of changing the clocks has a detrimental effect. They highlighted the significance of circadian rhythms—which are our daily physical, mental, and behavioral changes—and how moving the clocks forward in the spring when an hour is “lost” can disrupt these rhythms.

The society published a statement in the Journal of Sleep Research strongly recommending that Greenwich Mean Time (GMT)—when the clocks go back—should be kept throughout the year.

Spring Forward, Fall Back

In the UK, the clocks are set forward by one hour at 1 a.m. on the last Sunday in March and then set back by one hour at 2 a.m. on the last Sunday in October.

This period when the clocks are advanced by an hour is referred to as British Summer Time (BST) or Daylight Saving Time. Conversely, when the clocks are set back, the UK follows GMT or Standard Time.

The statement was issued by a team of researchers across the UK, spearheaded by Megan Crawford from the University of Strathclyde, Eva Winnebeck from the University of Surrey, and Malcolm von Schantz from Northumbria University.

Von Schantz emphasized that GMT aligns closely with the natural light-dark cycles of the day and night, and that exposure to morning sunlight is vital for maintaining optimal alignment of our body clocks with the day and night for improved sleep and overall health.

He further explained, “Switching permanently to GMT would align our clocks closely with solar time. While it may result in earlier sunsets in the summer, the health benefits from enhanced sleep and circadian alignment due to increased morning sunlight exposure from autumn to spring would outweigh this.”

Winnebeck pointed out that people often underestimate the impact of the one-hour time shift on their daily rhythms. She highlighted how Daylight Saving Time alters schedules by moving them forward an hour, causing individuals to get up and start their day an hour earlier than usual, especially during seasons with fewer daylight hours like autumn.

‘Misguided Idea’

Crawford stated that from a sleep and circadian health perspective, the notion of permanently moving the clocks forward is misguided. She stressed the importance of morning light for our body clocks to stay synchronized and explained that at higher latitudes like the UK, there is limited daylight during the winter months. Given the choice between morning light and afternoon light, scientific evidence favors exposure to natural light in the morning.

The practice of changing the clocks was initially introduced in the UK during World War I through the Summer Time Act 1916, following a campaign led by William Willett who never witnessed its implementation as he passed away before its enactment. Willett’s original proposal was to gradually move the clocks forward by 80 minutes in 20-minute increments on Sundays in April and then reverse the process in September.

British Summer Time commenced on May 21, 1916, and ended on Oct. 1 of the same year. During World War II, from 1941 to 1945, the UK operated on British Double Summer Time, being two hours ahead of GMT. There were numerous debates and inquiries in Parliament on clock changes between the late 1950s and early 1970s.

An inquiry during 1966–1967 led the Labour government of Harold Wilson to conduct the BST experiment, where the UK remained on GMT+1 throughout the year from Oct. 27, 1968, to Oct. 31, 1971, after which a return to the previous arrangement followed a free vote in the House of Commons.

While most countries globally including all EU nations observe daylight saving, there are exceptions like Iceland and Russia in Europe, along with countries like Japan, India, and certain African nations. Currently, there are no plans by the government to alter the existing daylight savings system.