TZ has for Kaliningrad a transition from CET to EET on 1 January 1945.

Zone Europe/Kaliningrad 1:22:00 -      LMT     1893 Apr
                         1:00   C-Eur   CE%sT   1945
                         2:00   Poland CE%sT   1946

This transition should probably be

Zone Europe/Kaliningrad 1:22:00 -      LMT     1893 Apr
                         1:00   C-Eur   CE%sT   1945 Apr 10
                         2:00   Poland EE%sT   1946

Note also the correction Poland CE%st to Poland EE%sT. Zone 2:00 is not CET.

Kaliningrad, the then German town Königsberg, fell to the Russian army only on 8 April 1945.
See Wikipedia https://en.wikipedia.org/wiki/Battle_of_K%C3%B6nigsberg

9 April 1945
During the last day of the battle, the besieged German defenders were overwhelmed and the defence coordination fell apart. Having been comprehensively defeated, and in the realisation that further resistance was futile, Otto Lasch decided on his own initiative to send emissaries to negotiate the surrender. At 18:00, the emissaries arrived at the Soviet lines, and a delegation was sent to Lasch's bunker. Shortly before midnight, the surrender was acknowledged.

Whether it transited to EET (2he) or to Moscow time (3he) is unclear, but what is certain is that from 1 Jan 1945 to 9 Apr 1945 it was still on German time.

Please note also the correction: 2:00 Poland CE%st to 2:00 Poland EE%sT. Offset 2:00 is not CET.