Hello!
The Dijon endings are sort of in order after each other, and I believe they're triggered by sleeping with people after Dijon. If you sleep with one character after sleeping with him first, it should trigger the second ending (make sure you go to sleep in the inn after sleeping with the second person to trigger it), and then if you sleep with someone else after that, it'll trigger the third and same for the fourth.
As for the 3rd dijon and jak ending, I believe that it's the one in which you don't choose either of them and let the time run out!