Why is the Change to Daylight Saving Time Offset?

westernman

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Algeria uses CET the whole year around. France uses CET in winter and CEST in summer. This really confuses some people who think that a meeting in summer at 14:00 CET is the same as 14:00 Paris time. And then get even more confused if your ask them did you mean 14:00 Algiers time or Paris time.
 

westernman

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Clarkson portrayed it well I thought, right down to the “woe is me I only made £20k last year”. He certainly showed how much work is involved and how hard it is to achieve anything without befriending and/or bribing the council.

There is a lot of money to be made by building a barn to keep the cows or tractors dry or something like that on agricultural land. Then once built you can gradually refine it into a rather nice house. After a few years, the house can no longer be the subject of a demolition order and can be sold as a nice barn conversion for real estate prices. There is a lot of money in attractive barn conversions in nice places in the country side.
 

LittleSister

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. . .

Anyone know why it's offset in that way with a bias of lighter evenings in the Autumn? Harvest gathering? Did they do it specifically to annoy me?

Yes, I think your guess is a good one. It may have been that the starting assumption was to change at the equinox, than the autumn one pushed back as most farmers would be in the middle of harvesting operations around the autumn equinox (though a minority, such as the viticulters in my example, harvest later), and the clock change then might be a disruption.

That said, the continuation of any clock change is just to annoy me. (I think we should be on BST all year, or better still tow the British Isles to somewhere nearer the equator for the warmer temperatures and more equal daylight hours.

(Failing that, when I come up on the pools I'll spend our wintertime in the southern hemisphere, and get the warmth and longer days both ends. :))
 

lustyd

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tow the British Isles to somewhere nearer the equator for the warmer temperatures and more equal daylight hours
Speak to anyone from there who has witnessed our summer to get the opposite view. They are amazed by our summer evenings and mornings. Consistent 12 hour days are rather dull when you think it through. I’m not a fan of very short winter days but it’s a reasonable trade off
 

Slowtack

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Who remembers the experiment in 1968 - 1971, keeping summer time throughout the year?
One effect I remember was that building sites had to start an hour later so couldn't get 40 hours in 5 days. We all had to turn up on Saturday mornings to make up the hours.
I recall going to school in pitch dark... Not very safe...
 

capnsensible

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Speak to anyone from there who has witnessed our summer to get the opposite view. They are amazed by our summer evenings and mornings. Consistent 12 hour days are rather dull when you think it through. I’m not a fan of very short winter days but it’s a reasonable trade off
Well except, say, Norwegians. Or Swedish. Or Finns, yadda yadda. Even the tartanistas get long days during June and July. It's basic geography.

The furthest north I've been in fresh air, I think, is Bergen.

But I do like the tropics. 13 hour daylight is good if you get up at sunrise. And it's lovely and warm. :cool:
 

lustyd

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But I do like the tropics. 13 hour daylight is good if you get up at sunrise. And it's lovely and warm
It’s all personal choice. I admit I quite like it getting dark at 8pm and staying warm, makes going out at night feel like going out at night!
Also easier to learn astro nav, in the UK it’s either too cold and cloudy to go out or it’s too light to see stars depending on season 😂
 

Sandy

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Clarkson portrayed it well I thought, right down to the “woe is me I only made £20k last year”. He certainly showed how much work is involved and how hard it is to achieve anything without befriending and/or bribing the council.
Is that gross or net profit on his hobby farm?
 

westernman

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Clarkson portrayed it well I thought, right down to the “woe is me I only made £20k last year”. He certainly showed how much work is involved and how hard it is to achieve anything without befriending and/or bribing the council.
See #42.
No need to bribe anybody.
 

Mark-1

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The latest sunrise of the year is around Jan 1st to 5th. That's about halfway between last weekend in October and last weekend in March.

Thanks, I reckon that answers my question, possibly combined with my harvest guess. Shocking that we have to guess and I still think it's dumb, but it's logical.
 
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LittleSister

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The latest sunrise of the year is around Jan 1st to 5th. That's about halfway between last weekend in October and last weekend in March.

Bring back the 68-72 experience full time 😁

Thanks, I reckon that answers my question, possibly combined with my harvest guess. Shocking that we have to guess and I still think it's dumb, but it's logical.

I am unpersuaded that is the explanation.

The last day of GMT before the clocks change in spring, solar noon is 12.13, day length is 12h 29m 46s, and civil twilight (when one can see to work outside) runs from 05.25 to 19.03.

The first day of GMT after the clocks change in the autumn, solar noon is 11.51, day length is 9h 46m 32s, and civil twilight is 06.21 to 17.19.

(Figures for Birmingham, 2023, courtesy of Timeanddate.com - Sunrise and sunset times in Birmingham, März 2023 )

The plot thickens! 😁
 

Mark-1

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I am unpersuaded that is the explanation.

The last day of GMT before the clocks change in spring, solar noon is 12.13, day length is 12h 29m 46s, and civil twilight (when one can see to work outside) runs from 05.25 to 19.03.

The first day of GMT after the clocks change in the autumn, solar noon is 11.51, day length is 9h 46m 32s, and civil twilight is 06.21 to 17.19.

(Figures for Birmingham, 2023, courtesy of Timeanddate.com - Sunrise and sunset times in Birmingham, März 2023 )

The plot thickens! 😁

I can see the logic. Some civil servant in 1916 just picked the same time either side of the latest sunrise, perhaps lighter autumn evenings for the Harvest was a bonus. (Or the other way round.)

But yeah, it does lead to a massive disparity which seems odd.

Of course we're discussing this when we can all google a graph showing the sunset/noon/day light hours. In 1916 even the policy makers might not have had that. Maybe they just didn't notice the implication.
 

ylop

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I can see the logic. Some civil servant in 1916 just picked the same time either side of the latest sunrise, perhaps lighter autumn evenings for the Harvest was a bonus. (Or the other way round.)
If you care enough - the parliamentary discsussions will be in Hansard and you'll see what the arguments for/against were.
Of course we're discussing this when we can all google a graph showing the sunset/noon/day light hours. In 1916 even the policy makers might not have had that. Maybe they just didn't notice the implication.
They had graphs in 1916! I think you can be pretty sure that in the middle of a world war they knew when sunrise and sunset were due across the UK. You can also be sure that any major decision would have been consulted with various ministries who would all have had access to this knowledge.
 

DanTribe

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This sort of thing mystifies me. The same hours are there, just with different labels, so someone was just being stupid if that story is true.
The exact details are hazy now but it involved changes to start and finishing times. The building site unions were strong in those days and getting agreement to changing working hours was difficult. A later start time should have meant a later finish but that couldn't be agreed therefore 40 hours could not be achieved in 5 days.
 

BabaYaga

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I am unpersuaded that is the explanation.

The last day of GMT before the clocks change in spring, solar noon is 12.13, day length is 12h 29m 46s, and civil twilight (when one can see to work outside) runs from 05.25 to 19.03.

The first day of GMT after the clocks change in the autumn, solar noon is 11.51, day length is 9h 46m 32s, and civil twilight is 06.21 to 17.19.

(Figures for Birmingham, 2023, courtesy of Timeanddate.com - Sunrise and sunset times in Birmingham, März 2023 )

The plot thickens! 😁
I found the OP's question very interesting and I think the answer might have something to do with the fact that apparent solar time varies over the year from mean (or theoretical) solar time, as explained here:
Equation of time - Wikipedia
The basic idea of DST, as I understand it, is to transfer daylight time that we are not using (because we are sleeping) from the morning to the evening, when we have more use for it, as we are awake then. This exercise is meaningful only as long as there is daylight time to spare during the morning hours – therefore no DST in winter (and a bit pointless in the middle of summer, when there is plenty of daylight during evenings anyway).
Looking at the graph of Equation of time in the link above, it is clear (I think) that there is an excess of morning daylight from around the time of autumn equinox, peaking at some +15 minutes around Nov 1st.
Contrary, looking at the period preceding spring equinox, there is a correspondent deficit of morning daylight (because the sun is late in relation to the theoretical solar time).
Addition: And theoretical solar time is the basis of clock time, although the latter is standardized within each time zone.
 
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westernman

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I found the OP's question very interesting and I think the answer might have something to do with the fact that apparent solar time varies over the year from mean (or theoretical) solar time, as explained here:
Equation of time - Wikipedia
The basic idea of DST, as I understand it, is to transfer daylight time that we are not using (because we are sleeping) from the morning to the evening, when we have more use for it, as we are awake then. This exercise is meaningful only as long as there is daylight time to spare during the morning hours – therefore no DST in winter (and a bit pointless in the middle of summer, when there is plenty of daylight during evenings anyway).
Looking at the graph of Equation of time in the link above, it is clear (I think) that there is an excess of morning daylight from around the time of autumn equinox, peaking at some +15 minutes around Nov 1st.
Contrary, looking at the period preceding spring equinox, there is a correspondent deficit of morning daylight (because the sun is late in relation to the theoretical solar time).
Addition: And theoretical solar time is the basis of clock time, although the latter is standardized within each time zone.

I see no need to mess around with the labels we attach to a specific time of day.
If we have more use for daylight in the evenings, then we can just get up later.

China manages with a single time zone whereas it really stretches across the equivalent of 5 time zones.

The USA makes a real hash of it, with multiple time zones and some states which change to/from winter/summer time and some which don't. Of course they could improve things further by having different states change at different times.

I see no point to summer/winter time.
 

capnsensible

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I see no need to mess around with the labels we attach to a specific time of day.
If we have more use for daylight in the evenings, then we can just get up later.

China manages with a single time zone whereas it really stretches across the equivalent of 5 time zones.

The USA makes a real hash of it, with multiple time zones and some states which change to/from winter/summer time and some which don't. Of course they could improve things further by having different states change at different times.

I see no point to summer/winter time.
I've tried so hard to care about it....... :)
 
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