I have to comments on this.

First of all work begins the time you arrive on the floor not the time you walk in the door. No one should be punching in before then in the first place. Time to remove your coat and ready yourself for work is not being on duty.

Is there not a set schedule to adhere to? I don't understand the concept of adding time - unless they are arriving late and trying to cover that.

What to do? Contact your HR department immediately. This is theft.