The General Electric WD21X33640 Dishwasher Timer regulates the wash cycle sequence to support proper operation in compatible dishwashers. This component manages the timing of functions such as water fill, washing, rinsing, and draining by directing electrical signals to different elements of the appliance during each stage of the cycle. It operates through an internal motor-driven mechanism that advances the timer contacts at controlled intervals, allowing the system to move from one function to the next. Typically installed behind the control panel and connected to the control knob and wiring harness, it works as a central cycle-regulating part. By maintaining accurate cycle progression, this timer assists in consistent washing performance and stable operation during typical dishwashing use.