In game timers.

When mousing over a friends name in your list, you can see how long they've been in game, what champion they're playing, and what map they're on. Lately I've notices that the length that my friends have been in game don't seem quite right. At times it's 5221:31 or 145:18. They're in SR normals so I doubt the timers have anything to do with them messing around trying to do some cool stuff. Plus, when I spectate those games the timers are actually just 21:23.