Currently the zone Europe/Kaliningrad has Zone Europe/Kaliningrad 1:22:00 - LMT 1893 Apr 1:00 C-Eur CE%sT 1945 Apr 10 2:00 Poland EE%sT 1946 Apr 7 3:00 Russia MSK/MSD 1989 Mar 26 2:00s 2:00 Russia EE%sT 2011 Mar 27 2:00s 3:00 - +03 2014 Oct 26 2:00s 2:00 - EET I wonder on which source this line is based: 2:00 Poland EE%sT 1946 Apr 7 It implies these time changes: 29 April 1945 from 2:00 to 3:00 like Poland DST 1 November 1945 from 3:00 back to 2:00 Russia took control of Königsberg/Kaliningrad in East Prussia on 10 April 1045. As a general rule, Russia imposed timezone 2:00 on occupied German territory in 1945, which is the same as German DST already in force from 2 April 1945. On 24 May 1945 Russia imposed double DST, making the effective time 3:00 east, until 24 Sept 1945, when it went back to 2:00 and then back to 1:00 (CET) on 18 Nov 1945. Now what happened in Königsberg? The Potsdam agreement of 2 August 1945 : (quote from Wikipedia)
The Conference has agreed in principle to the proposal of the Soviet Government concerning the ultimate transfer to the Soviet Union of the City of Koenigsberg and the area adjacent to it as described above subject to expert examination of the actual frontier.
Russia annexed the area on 17 October 1945, and integrated into the republic of Russia on 7 April 1946. Poland had no role to play in this matter. Regarding time regime, I would assume that the transition from 2:00 to 1:00 of 18 Nov 1945, for occupied Germany, did not happen in Kaliningrad. It was already annexed. It remained at 2:00 until 7 April 1946, when it was integrated and went to Moscow time. This transition on 7 April 1946 is also found in Shanks. Shanks does not have the double DST from 24 May to 24 September 1945, but I think he is wrong there. Why should the Russians have treated East Prussia from the rest of the occupied German territory in May 1945. That would make the zone table like this ( I marked the difference in red) Zone Europe/Russia/Kaliningrad 1:22:00 - LMT 1893 Apr 1:00 C-Eur CE%sT 1945 Apr 10 1:00 1:00 CEST 1945 May 24 2:00 1:00 2:00 CEMT 1945 Sep 24 3:00 1:00 1:00 CEST 1945 Oct 17 2:00 - EET 1946 Apr 7 3:00 Russia MSK/MSD 1989 Mar 26 2:00s 2:00 Russia EE%sT 2011 Mar 27 2:00s 3:00 - +03 2014 Oct 26 2:00s 2:00 - EET I have tried to simplify Zone Europe/Russia/Kaliningrad 1:22:00 - LMT 1893 Apr 1:00 C-Eur CE%sT 1945 Apr 10 1:00 SovietZone CE%sT 1945 Oct 17 2:00 - EET 1946 Apr 7 3:00 Russia MSK/MSD 1989 Mar 26 2:00s 2:00 Russia EE%sT 2011 Mar 27 2:00s 3:00 - +03 2014 Oct 26 2:00s 2:00 - EET but get an error: can't determine time zone abbreviation to use just after until time at this line in tzdata.zi 1 So CE%sT 1945 O 17 This is why I made the changes implied by rule SovietZone explicit