I know that Wikipedia is not reliable, still I would like to start with: http://ru.wikipedia.org/wiki/%D0%A7%D0%B0%D1%81%D0%BE%D0%B2%D1%8B%D0%B5_%D0%... Так, например, регионы Западной Сибири, ранее находившиеся в зоне MSK+4, перешли на время MSK+3, присоединившись к Омскому времени: Новосибирская область 23 мая 1993 в 00:00, Алтайский край и Республика Алтай 28 мая 1995 в 4:00, Томская область 1 мая 2002 в 3:00. В этих регионах фактически было отменено декретное время. Moves to Omsk Time 1993-05-23 Novosibirsk Oblast (Новосибирская область 23 мая 1993 в 00:00) 1995-05-28 Altai Krai, Altai Oblast (Алтайский край и Республика Алтай 28 мая 1995 в 4:00) Suggested new zone: Asia/Barnaul, split from Asia/Omsk 2002-05-01 Tomsk Oblast (Томская область 1 мая 2002 в 3:00) Supported by http://newsru.com/russia/01may2002/clock.html Suggested new zone: Asia/Tomsk, split from Asia/Novosibirsk If one looks at the map as of today http://efele.net/maps/tz/russia/ shows Asia/Omsk as two regions, in the west Omsk Oblast, interrupted by Asia/Novosibirsk in the east Altai Krai and Altai Oblast. Asia/Novosibirsk has Novosibirsk Oblast in the south and Tomsk Oblast in the north. Novosibirsk Oblast has Omsk Oblast in the west and the Altai entities in the east. That is the changes as written down in the Russian Wikipedia lead to contiguous zones at any time, while the current rules in tzdata do not. Omsk Time as in Omsk Oblast, joined by bordering Novosibirsk an eastward expansion, later joined by bordering Altai entities, an eastward expansion, later joined by bordering Tomsk, a northward expansion. Later joined by Kemerovo Oblast, an eastward expansion. This is covered by zone Asia/Novokuznetsk. -- Tobias Conradi Rheinsberger Str. 18 10115 Berlin Germany http://tobiasconradi.com/tobias_conradi