A lot of people are doing it everyday, advancing on to the next level every 10days, finishing at 30.
I aim for 6 days a week (sometimes it's 5) but didn't advance to level 2 until after 30 days. I'm taking my time with it and getting great results. I really don't like to push myself to the point of pure agony, I want to enjoy working out and not kill myself in the process. Like many others I am very out of shape and I am not in a race. As long as I continue to see my size slimming down I am happy.
The program says 30 days but I don't think it HAS to be 30 days..She says start at level one and when you're ready go on to level 2, and so on. So that's what I am doing. So far, so good.
I also log EVERYTHING I eat on Myfitnesspal...that's crucial.