Clocks in Europe shift back an hour on Sunday October 25, from the distorted “Summer Time” to more natural time.
Cartoon by Ian Dicks
American clocks won’t be restored to sanity till November 1.
That’s partisan language, and I make no secret of my contempt for the falsifying of clocks imposed on us, with many variations, by governments.
This topic comes around every spring and autumn, and it would be a bore to make every point about it every time. So I’ve now gathered what I want to say into another web page (“Clock shifting times”) that you can see under the “Astronomical Calendar Any-Year” tab at the top of this website.
The page is quite long, with a couple of time diagrams and a picture of what’s called in England a kissing gate, and sections on kinds of time, the history of the clock-changing custom, geographical differences, and so on. You may prefer to jump straight to my conclusion as to a better way.
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This weblog maintains its right to be about astronomy or anything under the sun.
My personal truce with daylight “saving” time: I keep my analog clocks and pocket watch on standard time year round. I like to see the clock hands straight up at noon and midnight. I just remember that noon happens around 1 pm and midnight around 1 am daylight saving time. I adjust my digital clocks and wristwatch back and forth for daylight saving time and standard time.
I hope that we will abandon this ill-conceived gimmick during my lifetime. In any event I plan to retire from work in a couple of years and mostly ignore clock time, so long as I’m able to get to meetings and events on time and make plans with friends and family.
Hello Guy,
To add to the self-inflicted distortions in the time zones consider the borders of the Eastern Time Zone. Its widest extent exceeds that of any of the other three Zones in the lower 48. The reason is that many would like to crowd into the Eastern Zone so their clocks read the same as New York and Washington DC, the nexus of economic and political influence. As a result we have Ohio – even the Upper Peninsula of Michigan – in Eastern Time!
Way out there in the western stretch of the Eastern Zone sunrises and sunsets are perpetually, by the clock, a good hour later than the clock readings at the eastern end of the Zone.
That’s the where and the why for the clamor for Daylight Time – kids in a zone’s “west end” waiting for the school bus, or grownups going to work, don’t have to do so in the morning dark (i.e., in civil or even nautical twilight).
Maybe Michigan would really be happier in the Central Time Zone.
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Back in the day, if I happened to be “on call” on the Saturday-Sunday night of the spring conversion to Daylight Time, I took a small solace that at least there would be one less hour that night for the phone to ring.
Of course, if I were on call the night of reversion to Standard Time in the fall, well …
Kenneth A. Heisler, M.D.
PS: I’ve reread and reread the penultimate sentence of the last paragraph of “The steps from natural time to artificial time” section which, in referring to clock time in the summer, states ‘Real 12 is called “11” and so on with every other hour.’
Should that “11” actually read as “1” ?
KAH
Another one of these places out of their logical time zones is Spain.which should really use Western European Time,like next door Portugal does and close by Morocco although Gibraltar, France and Andorra use Central European Time.i believe that Spain adopted CET under General Franco and talk about going back to WET but nothing ever comes of it.
I had never considered how the over-extension of time zones increases demand for daylight saving time. Thanks for pointing that out. We’ll probably never get back to local apparent time, so we’ll be living in time zones, and there will always be a need to compromise between political boundaries and 15-degree wide lunes* of the Earth’s surface. But citizens should be educated about how different time zone boundaries affect sunrise and sunset times at different longitudes and latitudes, and make informed decisions.
* I recently read _Heavenly Mathematics: The Forgotten Art of Spherical Trigonometry_ by Glen Van Brummelen. A lune is a two-sided spherical triangle! If you select any two points on a sphere that are poles to one another, i.e. the maximum possible distance from one another, and you draw two different lines connecting those points, the resulting figure on the surface of the sphere is a lune. All the rules about spherical triangles apply to lunes! The most familiar appearances of lunes in everyday life are the crescent and gibbous Moon, and orange slices.
Thank you for that term, “lune”. I have used “gore”, which I think means a slice of an umbrella, or a lune from one pole to the other of a system: for instance, a slice of the Earth from the north to the south pole. In that case the gore or lune is bounded by two lines of longitude. Lines of longitude are instances of great circles, but there is an infinity of other great circles around a sphere. Any lune is bounded by two of them. From a point on Earth, or on the celestial sphere, to its antipode – 180 degrees from it – there is an infinite number of great circles – all equal in being the shortest route – therefore an infinite number of possible lunes.
I have to use the equations for spherical triangles in my programming all the time; that is, they are buried deep in that programming. For instance, to find one angle of a spherical triangle from the opposite side and the two other angles, there is an elaborate equation involving the arc cosine of their sines and cosines. I merely found these equations in books, and I didn’t know they would work even if the “triangle” is a lune, with only two sides!
Oh, I notice you described the great circle as the “maximum” possible distance from one point to another: it is the minimum.
The “maximum” possible distance from one point to another, on any kind of surface, is a surreal idea! There would be an infinite number of such lines, as there are of great circles, but, unlike great circles, they would each take an infinite time to travel, even those whose ends are only a millimeter apart!
I should have said “maximum possible angular distance from one another”, i.e. 180 degrees.
The spherical trigonometry equations are the essence of nautical celestial navigation, which is the rabbit hole I’ve followed to the point where I’ve now read several books about them. I’ve tried to wrap my head around the equations, but I still have to just take them on faith.
Until the invention of the handheld scientific calculator celestial navigation was done with thick volumes of solutions for every point on the surface of the Earth, to an accuracy of one degree of longitude and one degree of latitude, and then interpolation between those points. Most navigators still use the tables — old habits die hard.
Now with an electronic calculator you can solve the equation directly to find your distance from the ground position of a celestial object (i.e. the point on the Earth where the object is at the zenith) and the azimuth toward that ground position, which tells you where you are. There’s still some fuzziness, because you have to use your assumed position, i.e. your best guess as to where you are, as one point of the triangle, with the North or South Pole and the ground position of the celestial object as the other two points.
That sounds like a transcendental equation: you have to put in the answer itself and keep approximating nearer to it.
Each figure in those printed older tables must have had to be found by a human “calculator” using pencil and paper.
Trigonometry is basically simple: everything can be reduced to a network of right-angled triangles. The sine and cosine of either of the other two angles are the proportions between the opposite, and the adjacent, side to the long side (the hypotenuse). But it’s the rapid calculation of those by a machine that is amazing.
In _Celestial Navigation in a Nutshell_ Hewitt Schlerith says that useful approximation is the essence of celestial navigation. You only need to find your position with sufficient accuracy to plot a course that will either (a) allow you to see your destination (lighthouses on high cliffs are easier targets than low atolls) or (b) give yourself a wide berth around unseen hazards.
Trigonometry is basically simple until you start to use it for any real world application. E.g.:
sine altitude = (sine latitude * sine declination) + (cos latitude * cos declination * cos polar angle)
Yes we should adjust human activity to fit the natural changes caused by Earth and Sun, but I would also eliminate the time zones and have Universal Time everywhere. It is not a new system, it is already used in Science and internally in computers.
“This graph shows sunrise and sunset times for latitudes 30°, 40°, and 50° north, approximating the contiguous U.S., which spans from 34° to 49°. ” I believe you meant 24, not 34
“The clock change…For America, it is 2 A.M. – Eastern Time!” The clocks change (where changed) at 2 A.M. *local* time. https://www.nist.gov/pml/time-and-frequency-division/popular-links/daylight-saving-time-dst
Your thoughts on Daylight Saving Time (DST) contain this comment…”But more than half of the world has, after trying it, abandoned it: all of South America except Chile and Paraguay, all of Asia except Israel, Lebanon, Syria, and Iran, all of Australia except its three southeastern states. ”
The Australian reference is not quite accurate. Four states and one territory in SE Australia make use of DST: New South Wales, Australian Capital Territory, Victoria, Tasmania and South Australia.
You also make no mention of New Zealand, which uses DST.
Corrections to the manifold details about clock-changing customs are welcome, and I’ll be able to incorporate them before we have to return to the subject for November 1 – let alone November 7 of next year!
Haha – I hear ya! I do an annual calendar for a group, so when I’m immersed in it, I’m a year ahead of myself. :D
You possibly missed one?the obscure Jervis Bay Territory often mistakenly thought to be an exclave of the ACT but infact a separate territory but administered by the ACT.the JBT is at the very south of NSW so almost certainly would have a noticable difference between winter and summer daylight so I reckon it must use daylight saving time too?
I considered including Jervis Bay Territory (JBT) – which you correctly note is a separate legal entity from the ACT – but decided against it. Firstly on the grounds of its obscurity; most Australians, let alone foreigners, wouldn’t know what it was. And secondly, unlike the other states and territories it has no parliament of its own and thus doesn’t decide whether or not to use DST.
The JBT is home,or was, to Australia’s only nuclear power station.
There was a proposal in the late 1960s to build a nuclear power plant in JBT. However it never went ahead.
Nov. 1st this year for American clocks. Interesting read about changing starting times instead of shifting the clock itself. That would definitely be a more natural solution. That solution reminds me of the time I spent working in India many years ago. When the hot season kicked in, we started the day an hour earlier, ended an hour later, and took several hours out of the hottest middle of the day. The time doesn’t shift around there, so it worked perfectly.
I personally eliminated the ludicrous twice annual changing of, at last count, over thirty different clocks both analog and digital in various rooms and appliances around my house, once I retired and just use EST all year round. It is a far simpler process to just make any necessary appointment during the government mandated DST period for one hour later than desired and to note the ‘real’ time in EST in my appointment calendar. I have always thought that with rare exception, employers should be happy with getting eight hours work a day from their employees and allowing the start of that period up to them. But then I am a rational individual who lives among an irrational herd of uniformist collectivists.