I don't have any option for unregistered users to post any comments. My server is located in Germany and I maintain a German community
Its always set to the right time (offset 0) and my users don't need to set their own timezone in the profile.
I don't know why Joomlacomment needs an offset of 2, when all other components work right with offset 0, the Joomla core works right with offset 0 and the server time shows the correct german timezone which is offset 0.
Joomlacomment only works right with an offset of 2 which wouldn't even be correct IF my server would run at GMT. In Germany I normally would have set an offset of GMT+1 then.
If its only possible to set the correct time in the user profile which would do a lot of problems (no frontend changing ever intended, new users have offset 0 at standard etc...) then I maybe have to change to JComments.
But at first I will look into the code and see how you did that in the 3 series. There it worked right without this timezone problems