My colony had to deal with a siege late in its first winter. A few days later, in the spring of the new year, I noticed one of my colonists create this piece of art:
(http://i.imgur.com/CwtDHZH.png)
It looks like the date has somehow gotten confused by the new year.
...or is it maybe some kind of prophecy? The colonist who created it had the "psychiatric patient" backstory, so maybe the voices in his head are whispering eldritch truths to him... :o
Strange.
Just to make sure; you have no mods installed, yes?
Well, my bad - I did have some mods enabled in this game, but only my own TMods. I just can't see any of those touching on systems that would cause this particular bug. But regardless, I accept this might invalidate the report. :)
Well, it doesn't necessarily invalidate the report, it just means that the bug must still be verified to happen in the base game.
A savefile would help in finding out what caused the bug.
13th of winter was already in 5501, february. There are 15 days in each season.
(in A17 however when winter ends the year ends)