Why is the Change to Daylight Saving Time Offset?

Mark-1

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It looks like (in the UK) we switch from GMT to BST in Spring when there's a about 12 hours of daylight, and from BST to GMT in Autumn when there's about 10 hours. So there's an offset to give longer evenings in the Autumn.

So it seems to me the spring clock change could have been mid Feb to give everyone longer evenings for an extra month. (I appreciate dawn and dusk times don't perfectly align with length of the day but you get my point.)

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?
 

capnsensible

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It seems to annoy a lot of people!

But the sun doesn't care. It will still plod along at 1 degree of longitude every 4 minutes. And wander down to around 23.5 degrees south, about turn and stroll up to 23.5 degrees north. As it ambles across the equator in the spring equinox, that's close to when summertime change happens in a lot of countries. Autumn equinox is about a month before the change. I'm sure there will be some historical reason.

Must be hard yakka altering Stonehenge twice a year.

Relatively speaking, of course........☀️
 

GHA

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why do countries use daylight saving, move the clocks an hour forward in summer. And why is the date typically at the end of march/october

Daylight saving time (DST) is the practice of advancing clocks during warmer months so that darkness falls at a later time of the day, typically by one hour. This practice is aimed at making more use of daylight and conserving energy. The date for the time change is typically at the end of March or October. In the United States, DST starts on the second Sunday in March and ends on the first Sunday in November, while in the UK and the European Union, summer time begins on the last Sunday in March and ends on the last Sunday in October. The specific dates were chosen to align waking hours to daylight hours to conserve energy, a concept first conceptualized by Benjamin Franklin in 1784
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. The modern idea of changing the clocks with the seasons can be traced back to at least the late 19th century when New Zealand entomologist George Hudson proposed it to conserve energy and extend summer daylight hours
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Mark-1

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why do countries use daylight saving, move the clocks an hour forward in summer. And why is the date typically at the end of march/october

Daylight saving time (DST) is the practice of advancing clocks during warmer months so that darkness falls at a later time of the day, typically by one hour. This practice is aimed at making more use of daylight and conserving energy. The date for the time change is typically at the end of March or October. In the United States, DST starts on the second Sunday in March and ends on the first Sunday in November, while in the UK and the European Union, summer time begins on the last Sunday in March and ends on the last Sunday in October. The specific dates were chosen to align waking hours to daylight hours to conserve energy, a concept first conceptualized by Benjamin Franklin in 1784
1
2
. The modern idea of changing the clocks with the seasons can be traced back to at least the late 19th century when New Zealand entomologist George Hudson proposed it to conserve energy and extend summer daylight hours
3
.

I can't see the bit that answers my question, can you quote the specific bit for me? (I did ask ChatGPT and googled without immediate success but it's more fun to ask here so I gave up and asked.)
 

DanTribe

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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.
 

GHA

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I can't see the bit that answers my question, can you quote the specific bit for me? (I did ask ChatGPT and googled without immediate success but it's more fun to ask here so I gave up and asked.)
various possibilities were given in the links provided by the AI (WHich does sometimes make things up but nothing compared to the cloud cuckoo land you get on here 😂)

"The specific dates were chosen to align waking hours to daylight hours to conserve energy, a concept first conceptualized by Benjamin Franklin in 1784"

US daylight saving time: When do clocks change and why was it created?
Daylight saving time - Wikipedia
Why Do We Change the Clocks, Anyway

"

"The modern idea of changing the clocks with the seasons can be traced back to at least the late 19th century when New Zealand entomologist George Hudson proposed it to conserve energy and extend summer daylight hours, something which would have benefited his own hobby of collecting insects after work."
 

Mark-1

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various possibilities were given in the links provided by the AI (WHich does sometimes make things up but nothing compared to the cloud cuckoo land you get on here 😂)

"The specific dates were chosen to align waking hours to daylight hours to conserve energy, a concept first conceptualized by Benjamin Franklin in 1784"

US daylight saving time: When do clocks change and why was it created?
Daylight saving time - Wikipedia
Why Do We Change the Clocks, Anyway

"

"The modern idea of changing the clocks with the seasons can be traced back to at least the late 19th century when New Zealand entomologist George Hudson proposed it to conserve energy and extend summer daylight hours, something which would have benefited his own hobby of collecting insects after work."

Ok, so you're saying that we offset it so a month's worth of Spring evenings are darker than Autumn evenings because it was better for a bloke in New Zealand to collect insects. Not sure that really makes sense - he might have wanted it lighter in Autumn evenings but that's no reason to have it darker in Spring - it would still have been more logical to pick mid Feb as the equivalent time to the Autumn change.

And TBH, I'm not even sure that it's saying that anyway - I think it's just saying that lighter summer evening's in general in Summer aided his hobby, not that an offset in the Spring/Autumn change did. And it's not really being that specific about it being a factor in the UK in 1916.
 

mjcoon

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various possibilities were given in the links provided by the AI (WHich does sometimes make things up but nothing compared to the cloud cuckoo land you get on here 😂)

"The specific dates were chosen to align waking hours to daylight hours to conserve energy, a concept first conceptualized by Benjamin Franklin in 1784"
(Without going so far as to Google...) I thought the point was for working, not waking, hours. Relevant before concepts such as flexible working were in vogue...
 

lustyd

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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.
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.
 

lustyd

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Did they do it specifically to annoy me?
No, there was a harmonisation a while ago to make most places change at the same time so it’s not scientific in any way just dates everyone could agree on and probably a compromise of the various dates there were before.
There’s currently an effort to remove summer time and various EU and or Nordic countries were trialling it I think
 

mjcoon

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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.
Similarly for farm workers. They may want the daylight, but at what time of day seems irrelevant. I suppose they are not quite so out of touch with the rest of the world while out in the fields as they used to be...
 

mattonthesea

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Remember that in the 60s flexible working did not exist. Everyone worked nine to five except for shop workers who had wed afternoon off and manual workers who worked sat mornings! What an outrageous idea to move working hours to suit the conditions😯.

I seem to remember that one of the reasons for returning to GMT was the number of Scottish children injured on the way to school on the dark. Caveat: could be wrong on that!
 

Bodach na mara

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Post #14 covers the basic idea, the dates of earliest sunset and latest sunrise do not occur at the either solstice. As stated in post #14, the latest sunrise doesn't occur until around 29th of December and this effectively governs the start of the working day. I used to hate returning to work after the Christmas season as I had to leave the house before it was light to walk the 2 miles along unlit roads to the station. Employers weren't really concerned about this as by the time people arrived at work there was sufficient light to be able to see, which was only really important for outdoor workers but the concept had carried over from the time before efficient lighting systems. I don't know exactly when the date of earliest sunset is but it is before the 20th of June, and the sunsets get earlier quite quickly after that, advancing about 2 minutes per day by mid July. However the sunrise lags again and it doesn't get inconviently dark in the late afternoon until October.
 
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