With the clocks going back this weekend, one organisation says that the United Kingdom should abolish the twice-yearly clock change and reinstate Standard Time throughout the year.
The British Sleep Society concludes from the available scientific evidence that circadian and sleep health are affected negatively by enforced changes of clock time (especially in a forward direction) and positively by the availability of natural daylight during the morning.
In 2018, the European Parliament voted to ask the European Commission to re-evaluate the future of DST in Europe (European Commission, 2018). In an online poll, respondents voted in favour of the abolition of twice-yearly clock changes.
In the UK, no progress has been made either to act (or not) on this European vote (much like in the other countries that have remained in the EU). There remains intense discussion around abolishing the clock change. Proposals include not only restoring Standard Time all year around, but also an alternative option of implementing permanent DST in the UK.
Morning light plays a central role in preventing our body clocks from becoming too late and in aligning them adequately with the 24-hr day.
This also means that morning light is crucial to allow us to initiate sleep early enough in the evening, and wake early enough in the morning (preferably naturally without an alarm clock) for work and school starts.
By contrast, light exposure during the late evening delays sleep onset and our natural waking, making it difficult to get up in the morning (which is then still our body’s nighttime given the circadian delay) and to obtain sufficient amounts of sleep.
In particular, individuals with very early work schedules or those struggling with too late sleep times for their schedules, such as teenagers who are prone to circadian delays, require optimal light exposure patterns to maintain adequate sleep patterns and durations. Although both sunlight and electric light exert these effects on our body clocks, sunlight has much greater potency in this circadian synchronisation because of its brightness and spectral quality
The custom of switching our clocks twice-yearly impacts our behaviour in relation to the timing of the opportunity for sunlight exposure.
It is sometimes erroneously assumed that DST provides us with more sunlight but, in fact, all we are doing is changing our behaviour by moving our schedules forward by 1 hr.
While this means there is an hour more sunlight afterwork/school, DST comes at an expense of 1 hr less sunlight before work/school, simply because we get up and travel to and from work/school 1 hr earlier.
During summer, sunrise in the UK is early enough, so that for most of the population the reduced opportunity for morning light is only theoretical.
This is because most people’s natural wake time is much later than sunrise during our summer months.However, the possibility of permanent DST (beyond summer and into winter) poses a potential danger to human sleep and health, primarily because of the resulting lack of natural light during winter mornings
Sunrises in winter occur considerably later than in summer, so if we were to get up an hour earlier as DST demands, this would result in a lack of natural light in the morning before we start our day. This would reduce our opportunity to advance our body clocks and obtain adequate sleep.
Several position statements, all of them arguing against the implementation of permanent DST, have been published by international sleep and biological clocks learned societies
However, none of these address the UK perspective specifically, and the impact that permanent DST would likely have on the UK population. To do this, we need to consider the unique geographical context of the UK.
