UTC+2 isn't very convincing as an argument for Russia. Only the Kaliningrad exclave uses that timezone, and if I were in a state-backed group, I'd live in one of the big cities.
Also quick search suggested UTC+3 was seen during the summer, and Russia doesn't do DST either.
Edit: some of the UTC+2/3 times are attributable to being differences in git committer and author dates (e.g. email patches)
I’ve always found this an amusing method of attribution considering top tier hackers are unlikely to be writing code only during office hours.
I couldn't let this be, so I went through the commits and as far as I can tell, that's the case. The committer/author names and timestamps are consistent with using --author on a commit (... or in a few cases, --amend --author).
Except one: commit 3d1fdddf9 has Jia Tan as both author and committer but the author timestamp is in +0300 while the commit timestamp is +0800.