Delay Wash Timer
Yes, that is the Delay Timer set knob (wheel). You dialed the number of hours you wanted to delay and it displayed in the window (1-9). When the start button was depressed the timer began to countdown. If no delay was selected the machine started immediately.
This machine was built by Whirlpool for Sears; it featured the power clean module, adjustable upper rack, and extra cutlery basket. It's a great dishwasher (assuming it's working!)
Hope someone gets it.