I am making progress.

An article in the newspaper Trud of 29 September 1981 lists the regions which did not return from DST to winter time in the autumn of 1981.

It comes from this website
https://vladimir-l-s.livejournal.com/35885.html

see image attached.

I had it OCRed and translated, and currently a colleague reading Russian checks the translation.
The relevant part seems to be:

- So, there will be regions of the country,
which, as it were, will remain in "summer" time?

- Yes. Firstly, these are those autonomous republics, krais, 'oblasts, Zatonomny okrugs' and raions, on the territory of which Moscow time or close to it used to be used in violation of the existing time zone boundaries. time worries everyone.

Here is the list:
autonomous republics - Dagestan, Kabardino-Balkaria, Kalmyk, Komi, Mari, Mordovian, North Ossetian, Tatar, Chechen-Ingush, Chuvash.

Territories - Krasnodar and Stavroregions - Arkhangelsk,
Vladimir, Vologda, Voronezh, Gorky, Ivanovo, Kostroma, Lipetsk, Penza, Rostov, Ryazan, Tambov, Tyumen, Yaroslavl;

as well as the Nenets and Evenk Autonomous
Okrug and Khatangsky district of the Taimyr (Dolgano Nenets) Autonomous Okrug.

In accordance with the new time zone boundaries on October 1, residents of Ust-May'sky, Ust-Aldansky and Oymyakonmogo, the regions of Yakutia and the Diva region of the Uzbek SSR do not change their clocks.




On 16.02.22 22:28, Stepan Golosunov wrote:
On Tue, Feb 15, 2022 at 07:44:35PM +0100, Alois Treindl via tz wrote:

correction: Rostov-on-Don is the larger city, with 1.1 million inhabitants

Well, the 3 largest cities in the affected area would be Nizhny
Novgorod (Gorky at the time), Kazan and Rostov-on-Don.  And which one
of them is larger changed with time.


On 15.02.22 19:39, Alois Treindl via tz wrote:

To me it seems that an extra zone is needed, which starts with LMT util
1919, later follows Moscow since 1930, but deviates from it between 1
October 1981 until 1 April 1982.

I suggest to call this zone Europe/Yaroslavl, because Yaroslavl with a
population of 608'000 seems to be largest city in the deviating area.