First hour of the stream is the run!

Edit from Over : I started the timer when you got the white cloak since you didn't took a "standard" start. We usually start a run by opening the menu, then "option" button then "yes" to be warped to Chapter Selection (CS), the timer should start at the moment you click on "yes" and we add +1:20m at the timer (the time to get on the CS). It should end when the 2 feets of the Journeyer reach the final walk where you lose control of the character. So in your case your run starts at 7:47 and ends at 55:00 + 1:20. So you did it in 50:07.