I found What Is And What Should Never Be (Wie es ist und wie es niemals sein sollte).
And I got to part 3 of 5, when Dean is scanning through the internet discovering all the people who died because him and Sam weren't hunting evil...and there, right on screen, was a DATE.
Short story shorter: I can now accurately, (with an error margin of +-1day), place a date on Phantom Traveler.
So, my AWESOME TIMELINE has been updated. It is now AWESOMER.
This Timeline update brought to you by: German, YouTube, and the number 5.
ALSO!! In this episode Bitch/Jerk is translated as Mistkerl/Idiot (Shithead?- literally "manure guy"/Idiot is pretty obvious). I asked a SPN community months ago what the German translation was, and as I recall, no one could tell me definitively. So, I'm happy I finally found an episode that had it.