I have the impression that some of the comments in the Russia section in file 'europe' have not been followed through in the actual zone tables. I refer to the lines beginning here # From Stepan Golosunov (2016-03-07): # 11. Regions-violators, 1981-1982. # Wikipedia refers to # http://maps.monetonos.ru/maps/raznoe/Old_Maps/Old_Maps/Articles/022/3_1981.h... # http://besp.narod.ru/nauka_1981_3.htm ... until # 12. Udmurtia Also the Russian wikipedia page https://ru.wikipedia.org/wiki/%D0%9C%D0%BE%D1%81%D0%BA%D0%BE%D0%B2%D1%81%D0%... contains the sentence (in Google translation)
In the autumn of 1981, Arkhangelsk, Vologda, Yaroslavl, Ivanovo, Vladimir, Ryazan, Lipetsk, Voronezh, Rostov-on-Don, Krasnodar and regions to the east of those named (about 30 in total) parted ways with Moscow time.However, the convenience of common time with Moscow turned out to be decisive - in 1982, these regions again switched to Moscow time.
Shanks International atlas has similar information, and also the Russian book Zaitsev A., Kutalev D. A new astrologer's reference book. Coordinates of cities and time corrections, - The World of Urania, 2012 Russian: Зайцев А., Куталёв Д., Новый справочник астролога. Координаты городов и временные поправки 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.