Sunday 28 October 2012

Daylight musings

Who said you can’t cram more than 24 hours into one day? Last Saturday I travelled to England from home and had a whole 2 hours extra. Now if you’re wondering why, there’s a perfectly logical reason. Firstly, the UK runs 1 hour behind Central European Time; and secondly, the last full weekend of October marks the end of Summer Time when the clocks get put back.

At the end of August, people are already talking about the ‘nights drawing in’, but by November we’re in completely new territory. Suddenly it’s getting dark at 5 in the afternoon and there’s still a month and a half to go before sunset times even start to creep upwards again. Unless you decide to move south of the Equator, there’s not a lot you can do to beat the gloom. Just grin and bear it as best as you can until the earth’s axis starts titling in ‘our’ favour again.

Time zones and seasonal time shifts are strange phenomena. At this time of year, I can’t help feeling happy about living in the west of a time zone. You have to feel for the Poles who have to put up with sunset times of 3.15 p.m. in the depths of winter, whilst the Spanish might still be enjoying some rays of winter sunshine – however feeble – almost 3 hours later. And of course, the further north you go, the shorter the days become. I once had a fascination with looking at webcams in northern Norway in deepest December, but gave up because they were suicidally depressing – and I don’t even live there.

Daylight saving measures were first mooted in the late 19th century and governments have been tinkering with them ever since. The map above shows the countries and states that currently implement daylight saving measures. They were actually brought in as a way of conserving energy in the summer months during the First World War, at first in Germany, and then the idea was quickly copied by other industrial powers in the northern hemisphere. The principle behind daylight saving measures is to make the best use of daylight in a way which benefits the majority of the population, taking into such factors of (road) safety and the needs of the economy. In the late 1960s, the UK government introduced British Standard Time, with clocks running on 'summer time' throughout the year, so in fact, the country was a full hour ahead of GMT. As I know from first-hand experience it meant going to school in the dark, but it was a lot lighter in the evenings. The experiment was abandoned in 1971 ostensibly on the grounds of road safety.

Even in a country as compact geographically as the UK, daylight lengths can vary considerably from the north to south. In winter, the Shetlands experience less than 6 hours of daylight around the solstice, whilst Cornwall in the far south-west has over 8. (Of course, the reverse is true in the summer, when there are 5 hours of darkness in the northernmost outpost of the British Isles.) Furthermore, there's almost an hour's difference in sunset times between the west and the east of the country. The variation in times and lengths of days means that there are advocates of change (or non-change) around the country. The Royal Society for the Prevention of Accidents (RoSPA) favours a return to British Standard Time, with summer time (GMT+1) all year round. Going one stop further, some business people argue for the adoption of Central European Time, where the UK would effectively join the same time zone as the rest of Europe. Outdoor workers and farmers in Scotland however, are loath to see any changes to the current system, reasoning that summer time throughout the year would mean sunrise times as late as 10 a.m. 

A report in the NRC Handelsblad at the weekend pointed out yet another complication caused by the time shift. Many scientists, like Till Roenneberg, professor of medical psychology at the Ludwig-Maximilian University in Munich – the subject of the NRC article - have argued that our body clocks are naturally attuned to sunrise and sunset times. By not listening to our biological clocks we put our health at risk. When the clocks change in the autumn, the additional hour, as well as the longer nighttime hours, give our bodies time to adjust and recover our natural sleep patterns. In the spring however, the ‘loss’ of an hour can take as much as a month to recoup in terms of sleep. Other studies have revealed that both suicide rates and the incidence of heart attacks increase after summer time comes into effect in the spring.

Changing the clocks poses other intriguing problems as well. I've often wondered what train drivers do in the middle of the night when the clocks go back. Presumably they go more slowly, or maybe stop for a nap and a cup of tea. And do they get paid overtime for this ‘extra’ hour? Self-evidently the reverse applies in spring when – somehow – they have to make up time. One supposes that traffic is scarce at that time of night anyway, so they can put on a spurt.

So what did I manage to do with those two extra hours? Simple: I spent my time penning this time-related blog.