I can't realy verify this as I previously fiddled with my logs a bit, so it is possible that the not saving was due to my part.
However, this doesn't go for all the logs I have/had.
Some chats I had lately (in late october) with a few people where well after I had fiddle (tested) something with the logs (begin october). They are indeed not saved to a new "october 2005" folder. The eventslog is also reset and starts at 1/11.
But I also can't verify if the logs where created in the main log directory during october in the first place, because I didn't looked at it since begin october until now. Chatting with someone now (november) does create a log in the main log folder though.
So, at the least, I can indeed say there is something going on (or better: not going on?) and more testing needs to be done to pinpoint it exactly.
This said, I do have folders for october 2003 and 2004 (but can't verify if I created them or if Plus! created them)...
EDIT1: what I also just notice now is that the archived event logs for various months contain some lines for the next months also. => EDIT3: this is a small timing issue according to Patchou.
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EDIT2: Sunshine PM'ed me about this. She has the same problem as me: she can't confirm this with 100% certainty due to fiddling, but she also doesn't have an october folder either.
However she noticed that all the october logs are put in the september folder! And this is indeed also what happened with my logs after verifying this... And logs with the same name are renamed to email@server.com.txt.1.txt
This is however nothing new and apparently
a very old bug, since my october 2004 logs are indeed also in the september 2004 folder. (though can't verify if this also was the case for the september 2003 folder; I may have moved the logs from there manually)...
I also have no clue what-so-ever as of why this could happen. The best guess I can make is it has something to do with the double digit in october (10) apposed to the single digit in september (9) internally, but this guess can be way off.
(EDIT3 => and one of my other guesses was it had something todo with DST, but since it was unlikely at first sight I deleted that from this post again... now it seems it has something todo with it afterall, for some stuff still, doesn't explain why "october" wasn't created)
pfff I really don't know..., and thus I'm very curious in hearing from Patchou about this and why it happens.