Sunday 30 October 2011

Putting clocks back-and-forth - a pointless waste of human life


This ridiculous business of putting clocks backwards and forwards twice a year gets me more annoyed every time it happens.

It is so stupid that if it didn't already exist it would be utterly inexplicable, an exotic tribal custom.


The basic problem is that in the West we have adopted a work timetable of roughly 9-5 (09.00-17.00) which has three hours before noon and five hours after noon.

But to maximize the useful daylight we should arrange the working day so that (if you are on or near the longitudinal time line) noon falls in the middle of the working day with an equal amount of daylight either side.

This is, for most people, enough to get to and from work because the sun still cast a fair bit of light for a while before and after sunset (unless it is very cloudy).


But instead of changing the working day to fit with astronomical reality, we mess about with the clock.

British Summer Time puts the clock time forward, so that noon is at 13.00h, which means that the average working day is then equally distributed around noon - for an 8 hour day, four hours before noon, and four hours after.

We have this arrangement during 'summer' - but then the nonsense sets in. We reset the clocks to Greenwich Mean Time, as happened last night.


At extreme latitudes the different day lengths in summer and winter create problems. For example, I live at about 54 degrees North, and at the winter solstice there are only about 7 hours between sunrise and sunset; while at the summer solstice it is only fully dark for about 3 hours.

The summer has so many daylight hours that the clock change makes no significant impact. But in the winter, it really does become important to maximize the use of daylight. Yet we change the clocks such that noon falls less than halfway through the working day, and it is pitch dark by the time many people finish work.


And what about the timing of this change?

The Autumn Equinox is on 21 September, and we are by now only seven and a half weeks from the Winter Solstice (Dec 21) when the days are shortest.

By that logic, we should switch back to Summer Time seven or eight weeks after the Winter solstice - about 12 February.

But we don't. In fact we go back to BST on 25 March, which is after the Spring Equinox (21 March).

Please don't try to explain the logic behind this - because there is no sense in it.

Yet this is what everybody in Europe actually does: changes the clocks about 8 weeks before the Winter Solstice, and then restores them 13 weeks afterwards.


What I most hate about this business of changing the clocks - aside from the inconvenient waste of time, millions of man hours twice a year in England alone; and the disruption to circadian rhythms leading to sleep disturbances, which in the case of children may take a week or two to set right - is that the process distances us from astronomical reality.

If modern humans will not acknowledge the basic astronomical framework of the world we live in, and adjust human timetables to the timing of the rotation of the earth and the orbit around the sun of a tilted planet - but instead try to fit cosmology around our timetables by manipulation the measurement of time - then we are living in a world of dangerously extreme and irrational abstraction.

Which, of course, we are.



The Crow said...

What is this compulsion to observe such abstract concepts as "sense"? What is this "sense" thing, anyway? Thank heavens it finally appears to be dying out.
It's about time. Which reminds me...
Time. Yes. I don't pay too much attention to it, really. My timepieces have all either stopped, or are set to whatever seasonal orientation was in effect whenever it was they were last set.
This suits me. I find I am a:-on time, b:-an hour early, or c:-an hour late. Which generally turns out to be about as punctual as anybody else is, anyway, if not more so.

That said, I confess, I probably agree - at least in principle - with you.

Anonymous said...

Peter S. said:

It will no doubt please you to hear that the monks of Mt. Athos still use the medieval unequal hour day convention, where the hours between sunrise and sunset are divided into twelve equal hour divisions and the hours between sunset and sunrise are divided into twelve equal hour divisions of different length than those of the daylight hours, the difference in lenght varying with the time of year.

Kristor said...

John Michell makes the same point about the metrical system, versus the ancient and venerable English system of measurement. He points out that the English, Greek, Roman, Hebrew and Egyptian feet, while all different, are all commensurable with each other by means of certain numbers held to be canonical for the whole universe by the ancients. They all, furthermore, bear simple relations to the diameter or circumference of Earth, the Moon, the mean distance between Earth and Moon, and so forth. Ditto for the furlongs, cubits, yards, miles, acres, and hectares of each of the ancient systems of measurement. They are related to astronomical realities to a far greater degree of precision that the metrical system of the atheist philosophes. And this is why they are used at, e.g., Stonehenge, Jerusalem, Glastonbury, etc. Furthermore, they are duodecimal, so that they are related to the geometry of the sphere, and thus to navigation, surveying, and - perhaps most importantly - to the passage of time. It is the ancient systems of measurement that relate the second of time to the second of arc on the surface of the Earth - that, i.e., relate better to human life as actually lived.

Likewise for the old Fahrenheit system versus the newfangled Celsius system. The former divides into 100 degrees the range of temperatures actually sampled across Europe over several years circa 1800.

dearieme said...

"The basic problem is that in the West we have adopted ..": that's a bit parochial.

But even sticking to this parish: perhaps you can explain to me the strange British habit by which the officer class works a nominal 9-5 while many of the other ranks work a nominal 8-4.

Anonymous said...

One's circadian rythms are set by the light of dawn, and by eating breakfast. When it becomes light, one tends to wake up.

So, the logical way to set the clocks is so that dawn happens at the same time of the clock each day - which, however, would result in days being slightly more than twenty four hours in autumn, and slightly less than twenty four hours in spring.

Supposing we wish to make such adjustments infrequently, we should set the clocks forward one morning in spring, and backward one morning in autumn.

Which is approximately what we do.

If our circadian rhythm is set by the light of dawn, daylight saving keeps clocks from getting too far out of synchrony with our circadian rythm.

Kristor said...

@ dearieme: aside from the great state of Indiana, we in the US do the same absurd thing with our clocks twice a year. I hate it.

Also, our officers and enlisted men all work a nominal 9 to 5. What this means in practice is that enlisted men work 9 to 5, while officers work 8 to 7 or so. In general. In the private sector, anyway.

Bruce Charlton said...

@Peter S - it does please me! But I wonder how practical that would be at high latitudes where the daylight varies between 7 hours and about 18.

On the other hand, maybe it makes ense to spend nearly all of winter days in worship, and most of the rest of the time asleep.

@Kristor - never knew that about Farenheight. It explains why it is so hard to give-up.

JAD - That would, indeed, be a logical reason - although obviously it is not the reason since people would be much more aware of the importance of early morning light especially in winter at high latitudes.

But it would be impractical always to rise at dawn in the UK, N. Germany, Scandinavia etc where day length varies by so many hours.

Daniel said...

I don't know the story in the UK, but here in the US I've always been taught that it was a result of the merging of the Agricultural America with Commercial America. That is, Commercial America can keep the clocks the same without change. And Agricultural America revolves around the sun (as it were). In order to keep the two milieux in synch, it was necessary to adjust the "official" clocks to the lived reality of the farmers. It's confusing to me, but not an absurd notion.

But though we still grow an awful lot of corn in this country (an obscene amount of corn!), the whole justification for the adjustment system has fallen by the wayside. People — office workers who grow mightier by the day and farmers who grow lesser by the day — get up when they get up. No one cares what the clock says. In any case, I do understand the impulse behind the original idea.

Incidentally, I'm interested in latitude. Here in Seattle we are at 47 degrees N. It's by far the northernmost major city in the US.

Boston "back east" and Minneapolis-St. Paul in the "midwest," are more "northern" in the popular imagination, because they are older cities and they have far more severe winter weather (especially the Twin Cities). But MSP is at 44 degrees, and Boston at 42. Seattle is MUCH farther north than either, or than any other American city (unless you count Anchorage as a "major city," which I do not).

Seattle doesn't get much snow or severe cold, but it's DARK in the winter, like European cities are. I note that London, the "mild southern" city of the UK is at 51 degrees, much higher north than even Seattle.

Light speaks to people, and sometimes I wonder about the influence of latitude on character. I'm proud of Seattle's northernmost status, and make a point of explaining it to Bostonians who complain about their (admittedly) colder winters.

Seattle is very far progressed in its Europe-ification, in terms of being the bleeding edge of American leftism. But it's also very charming, very peaceful (low murder rate, etc), very community-oriented, very literate, etc. There's a hardcore of Northern Europeans (mainly Anglos and Scandinavians) who maintain the Seattle culture day-by-day.

Much older, more historical cities like Philadelphia, Atlanta, and Chicago are much more vulgar places. I know race, demographics, and history have a lot to do with this. But sometimes I can't shake the feeling that it's the northern light itself that's maintaining our little island of loveliness.

Bruce Charlton said...

@Daniel - I suspect there is a threshold at which latitude becomes a factor, but maybe 47 degrees is not far enough (still south of Paris).

In nothern Britain many people take steps to expose themselves to bright (necessarily artifical) light near the winter solstice, and feel better for it.

Icelanders seem to have been subjected to significant natural selection for their ability to cope with short days - which shows that it makes enough difference to the un-adapted to reduce their reproducive success.

I once wrote/ compiled a radio program about this:

So I certainly agree there is something very appealing about Northern-ness (Lewis and Tolkien were brought-together as friends by sharing this feeling) - but it is also something to be coped-with. Technology helps!