Old Father Time

This clock, which arrived today in my office, slices up time. The tick, tock and the swinging pendulum skim off the seconds. The single bell marks off the half-hours. The deep, slow chimes strike off the hours. And yet, if the face were covered and the chimes stopped; with just the pendulum in movement and the tick tock, it would be impossible to tell which way time is flowing; forwards or backwards?