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February 2017

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Re: [tz] Help needed on Tz database
by Bill Seymour Feb. 2, 2017

Feb. 2, 2017

Hi, François, I'm surprised that that old paper is still around. I wrote it mainly for my own benefit when I was trying to understand the tz source files. The way I read the C-EUR rules is that there was a switch to summer time in 1940, but no change back until 1942; so when Minsk changed to C-EUR, the steady state implied by the most recent C-EUR transition would be UTC+1:00; and so the wall clock time in Minsk would be UTC+2:00 and the abbreviation would be CEST. But I'm just an amateur at civil time. I'm including the tz mailing list in this message's recipients in case somebody who really knows will correct me if I'm wrong. 8-) --Bill On Thu, Feb 2, 2017 at 1:25 AM, Francois Rouleau <rouf0007(a)gmail.com> wrote: > Hi > I read "How to read the Tz Database" but there is a case (maybe more later) > that I dont understand. From https://www.timeanddate.com, for Minsk, I see > that: > > "Saturday, June 28, 1941, 12:00:00 midnight clocks were > turned backward 1 hour to Friday, June 27, 1941, 11:00:00 pm local > daylight time instead" > > > > Zone: > ===== > > # Zone NAME GMTOFF RULES FORMAT [UNTIL] > Zone Europe/Minsk 1:50:16 - LMT 1880 > 1:50 - MMT 1924 May 2 # Minsk Mean Time > 2:00 - EET 1930 Jun 21 > 3:00 - MSK 1941 Jun 28 > 1:00 C-Eur CE%sT 1944 Jul 3 > 3:00 Russia MSK/MSD 1990 > 3:00 - MSK 1991 Mar 31 2:00s > 2:00 Russia EE%sT 2011 Mar 27 2:00s > 3:00 - +03 > > Rules: > > RuleName From To Month Day Start Add S/D > Rule C-Eur 1917 1918 - Sep Mon>=15 2:00s 0 - > Rule C-Eur 1940 only - Apr 1 2:00s 1:00 S > Rule C-Eur 1942 only - Nov 2 2:00s 0 - > Rule C-Eur 1943 only - Mar 29 2:00s 1:00 S > Rule C-Eur 1943 only - Oct 4 2:00s 0 - > Rule C-Eur 1944 1945 - Apr Mon>=1 2:00s 1:00 S > Rule C-Eur 1944 only - Oct 2 2:00s 0 - > > > Question: > > On June 28, 1941, the C-Eur rule takes over. What row of the rule section > should I look at? > > Is it the letter column (in rule) that will tell me if this new time is STD > or DST ? > > > Thanks > > François >

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