Indigo Domotics

Has anyone been able to figure out a way to detect if a Roomba fully completed a job or not? I'd like to add logic where I start my Roomba when I'm not home, but skip if it had competed a full cleaning recently.

My best idea so far is to calculate the amount of running time the Roomba has had in the past X hours and take a guess based on the average time it takes to complete a full job for my house. Wanted to see if anyone had a better idea.