Going by the Tag that's on my wrist, I'll say it's the stopwatch second hand. Top left dial is stopwatch hours. Top right is stopwatch tenths which doesn't move until you press the lap or stop buttons. Bottom center is stopwatch minutes. I don't have 4 hands on the main movement, but my stopwatch only goes to 30 minutes.
On this picture, the red hand on the main movement is stopwatch seconds. The top left is stopwatch minutes, top right stopwatch tenths. Bottom center is the "current time" second hand.
