We both used the in game timer provided by dying light.My run starts at 19:05 and ends at 39:10 ( including the time displayed after We did the pvp part). Here is the video proof:

Here is blink ( player 2 video proof) where he also uses in game timer. His run starts at 0:30 and ends at 19:10. Here is the video proof: ( he also takes some time after to show the pvp and he has a second part in case you want to see the final time display after the pvp fight ended)