This could be due to your saved game becoming corrupt. Unfortunately I know no way of solving this but if anyone does then feel free to post and I will add it to the OP. Your saved game is probably corrupt if it works fine but the game always crashes at certain date, no matter how many times you try. If your other saved games work fine then your saved game has probably become corrupt. You can prevent corrupt saves from being too disastrous by constantly backing up your game so you can reload to a point that's not too far back from the affected save.
I had this happen to me once, and I had the 3 part rolling autosave every month. It would crash in October 2011 every time I loaded the September autosave. But then I loaded the August autosave, I was able to get through it fine. Sometimes random stuff makes it corrupt.