I've written several times about converting calendar dates from Julian to Gregorian, and how part of Poland switched from Gregorian to Julian in the 19th century under Russian control. (example).
So, since I knew that the Poland where my ancestors lived was under Russian control at the time, you would think when I discovered a 19th century marriage record in a Polish database, it would occur to me that there were multiple languages it could be written in? And that perhaps the most likely was not Polish.
Well, anyway, I've been informed that I need to find a Russian translator.