Quote from Mauste:
"The timer starts when you start a new game, is active during cutscenes and in the hub world, and stops when the player sees the newspaper at the end. It is inactive when paused."
I actually don't believe that at all. Then a 38m Real-Time on Wii U and a 35m on PC shouldn't get approximately the same In-Game time. Unless it all has to do with frame-rate factors or other adjustments.