Soo, I was in the middle of a PvP2 game when we all decided to go on a spontaneous sledding outing at midnight, so I left, forgetting in the confusion that I forgot to quit the game. Came back at 3 or 4, saw that my (unplugged) laptop had hibernated in the meantime, decided I was too tired to boot it up, so plugged it in and went to bed.
I woke up to this:

54124 seconds -> 902 minutes -> 15 hours...sounds about right. Apparently the guy had quit the game or something and the timer kept counting.