Some people look at their wrist watch constantly to appear busy or because they are waiting for something.
Sometimes when I'm bored I will look at my wrist watch constantly or even my clock on my phone to see what time it is.
If someone keeps looking at their wrist watch constantly or looking at the time it is a sign that they are most often bored by you or someone and are counting down the minutes until they can leave.
Even when I'm at work I look at my wrist watch constantly and even at the clock on the wall to see what time it is and hope that it would speed up so I can get out of the office and go home.