Dishwasher Cycle Length excessively long

Could be normal, depending on the cycle. 4 hours would be the longest cycle, and the sensor readings in the tub determine to continue washing or not. The average is 2 hours fr cycle these days. Some units do have a quick cycle as well. Here is a great blog on it from Whirlpool’s own website addressing just this.

https://www.whirlpool.com/blog/kitchen/how-long-do-dishwashers-run.html#:~:text=How%20long%20does%20a%20dishwasher,heat%20water%20between%20cycle%20phases.