The first entry in the europe zone file for Ireland is as follows: Rule GB-Eire 1916 only - May 21 2:00s 1:00 BST However I don't think it's correct. I'm not sure how far back we want to go, but apparently from 1880 up until October, 1916, Dublin was 25 minutes off from London. When the clocks were set back in October 1916, they were set back 35 minutes - which would seem to cast doubt on the second line for GB-Eire: Rule GB-Eire 1916 only - Oct 1 2:00s 0 GMT And 25 minutes, as noted in the file was an oversimplification. A web page with more detail is here (I've cc'd Dave who might have more info): http://www.maths.tcd.ie/~dwmalone/time/dunsink.html And apparently there were places in Ireland observing the Dunsink based "Dublin Mean Time" up to the 1940s: http://historical-debates.oireachtas.ie/D/0079/D.0079.194003050027.html In addition, Belfast seems to have had yet another timezone. How did the British actually manage to build an empire anyway? Kevin -- Kevin Lyda Dublin, Ireland US Citizen overseas? We can vote. Register now: http://www.votefromabroad.org/
On Sun, 16 Oct 2011, Kevin Lyda wrote:
The first entry in the europe zone file for Ireland is as follows:
Rule GB-Eire 1916 only - May 21 2:00s 1:00 BST However I don't think it's correct. I'm not sure how far back we want to go, but apparently from 1880 up until October, 1916, Dublin was 25 minutes off from London. When the clocks were set back in October 1916, they were set back 35 minutes - which would seem to cast doubt on the second line for GB-Eire:
Rule GB-Eire 1916 only - Oct 1 2:00s 0 GMT
The effect as shown by zdump appears to be correct: Europe/Dublin Sun May 21 02:25:20 1916 UTC = Sun May 21 01:59:59 1916 DMT isdst=0 gmtoff=-1521 Europe/Dublin Sun May 21 02:25:21 1916 UTC = Sun May 21 03:00:00 1916 IST isdst=1 gmtoff=2079 Europe/Dublin Sun Oct 1 02:25:20 1916 UTC = Sun Oct 1 02:59:59 1916 IST isdst=1 gmtoff=2079 Europe/Dublin Sun Oct 1 02:25:21 1916 UTC = Sun Oct 1 02:25:21 1916 GMT isdst=0 gmtoff=0 That is, the clocks went forward one hour at 2am DMT on 21 May, and then at 2am DMT (3am summer time) on 1 October they went to GMT. See attached scans of the relevant laws. The relevant UK National Archives file has a public information poster used in Ireland to inform people of the 35-minute clock adjustment. What times people were actually using in Ireland, I don't know. I have not attempted a thorough survey of Irish laws relating to time; my 2005-01-26 comment in the europe file lists those I found (though those URLs seem to have become broken since then) but I haven't attempted to match them up to individual transitions and add comments for each transition giving the Irish legal basis for it alongside those giving the British basis. -- Joseph S. Myers jsm@polyomino.org.uk
Europe/Dublin Sun May 21 02:25:20 1916 UTC = Sun May 21 01:59:59 1916 DMT isd Europe/Dublin Sun May 21 02:25:21 1916 UTC = Sun May 21 03:00:00 1916 IST isd Europe/Dublin Sun Oct 1 02:25:20 1916 UTC = Sun Oct 1 02:59:59 1916 IST isd Europe/Dublin Sun Oct 1 02:25:21 1916 UTC = Sun Oct 1 02:25:21 1916 GMT isd
That is, the clocks went forward one hour at 2am DMT on 21 May, and then at 2am DMT (3am summer time) on 1 October they went to GMT. See attached scans of the relevant laws.
My understanding is similar to this: we had both summer time and then later a switch to GMT in 1916. This is based on the two acts that you attached. I has started searching the newspaper archives, but I seem to have skipped 1916 and gone on to the 1940s to look for information about double summer time, which we didn't have, but Belfast did (see the note transcribed from the Irish Times below - it was followed on subsequent days by notices about differences in train times, radio schedules, etc...)
The relevant UK National Archives file has a public information poster used in Ireland to inform people of the 35-minute clock adjustment. What times people were actually using in Ireland, I don't know.
I'd be interested to see this, if you have a copy.
I have not attempted a thorough survey of Irish laws relating to time; my 2005-01-26 comment in the europe file lists those I found (though those URLs seem to have become broken since then) but I haven't attempted to match them up to individual transitions and add comments for each transition giving the Irish legal basis for it alongside those giving the British basis.
I did a check a few years ago, probably after 2005, and found very little relating to time, other than SIs implementing EU directives. We did do a cleanup by scrapping old statuates recently, and I skimmed it for time related acts. There was one "On the Measurement of Time", but when I checked, it was a transcription error and it was really "On the Measurement of Lime". David. Saturday, April 4, 1942 ----------------------- Double Summer Time Double British Summer Time, which applies also to Northern Ireland, begins at 2 a.m. to-morrow by the clock, which is already one hour in advance of greenwich mean time. Clocks are put forward one hour. Double Summer Time ends on Sunday, August 9th.
On Sun, 16 Oct 2011, David Malone wrote:
The relevant UK National Archives file has a public information poster used in Ireland to inform people of the 35-minute clock adjustment. What times people were actually using in Ireland, I don't know.
I'd be interested to see this, if you have a copy.
I didn't get a copy. http://mm.icann.org/pipermail/tz/1999-September/001712.html is what I wrote at the time about that research session, and my notes don't give any more information about that poster (in particular, I didn't note any page reference within HO 45/10811/312364 for the poster, so requesting a copy remotely would probably involve paying for National Archives staff to go through the file to locate the poster based on a description). -- Joseph S. Myers jsm@polyomino.org.uk
On Sun, Oct 16, 2011 at 14:43, Joseph S. Myers <jsm@polyomino.org.uk> wrote:
The effect as shown by zdump appears to be correct:
Europe/Dublin Sun May 21 02:25:20 1916 UTC = Sun May 21 01:59:59 1916 DMT isdst=0 gmtoff=-1521 Europe/Dublin Sun May 21 02:25:21 1916 UTC = Sun May 21 03:00:00 1916 IST isdst=1 gmtoff=2079
You're correct, I should have read further: Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2 -0:25:21 - DMT 1916 May 21 2:00 -0:25:21 1:00 IST 1916 Oct 1 2:00s That's why it's correct. However now I'm wondering about the first line there. Shouldn't it have been -0:25:21 from 1880? Kevin -- Kevin Lyda Dublin, Ireland US Citizen overseas? We can vote. Register now: http://www.votefromabroad.org/
Kevin Lyda said:
In addition, Belfast seems to have had yet another timezone.
I'm not sure what the issue is.
From the introduction of standard time in 1880 until 1916, Great Britain was on GMT and Ireland (all of it) on DMT.
In 1916, Ireland moved to GMT so that the whole of the UK was on the same time. In WW2, the UK (including Northern Ireland) had double summer time but the Republic of Ireland didn't. So there's Great Britain, Northern Ireland, and the Republic, with three different histories.
How did the British actually manage to build an empire anyway?
By accident. -- Clive D.W. Feather | If you lie to the compiler, Email: clive@davros.org | it will get its revenge. Web: http://www.davros.org | - Henry Spencer Mobile: +44 7973 377646
On Sun, Oct 16, 2011 at 14:40, Clive D.W. Feather <clive@davros.org> wrote:
Kevin Lyda said:
How did the British actually manage to build an empire anyway?
By accident.
And mostly in an era when time wasn't as critical as it is nowadays. -- Jonathan Leffler <jonathan.leffler@gmail.com> #include <disclaimer.h> Guardian of DBD::Informix - v2011.0612 - http://dbi.perl.org "Blessed are we who can laugh at ourselves, for we shall never cease to be amused."
On 17/10/11 01:37, Jonathan Leffler wrote:
On Sun, Oct 16, 2011 at 14:40, Clive D.W. Feather <clive@davros.org <mailto:clive@davros.org>> wrote:
Kevin Lyda said: > How did the British actually manage to build an empire anyway?
By accident.
And mostly in an era when time wasn't as critical as it is nowadays.
It's a mystery. What did they do with dates and times in telegraph messages? jch
participants (6)
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Clive D.W. Feather -
David Malone -
John Haxby -
Jonathan Leffler -
Joseph S. Myers -
Kevin Lyda