Because the 5dpt is a tool to help us re-discover our pouch and to banish the carb monster, it really only needs to be done when we feel ourselves slipping (or have already fallen down the slippery slope). Once you've done the 5dpt, as mentioned before, you can stay on day 6 for as long as you'd like!

The 5dpt is not a diet or an eating plan and shouldn't be used as such. Day 6 (eating protein first, with complex carbs added in) will serve you well in the "diet" phase. You'll be surprised how quickly the weight comes off when you're aren't ingesting simple carbs.
That being said, after the first time I did it, I did well until my son's birthday - where I had a few too many carbs and I could see myself starting to slip. As such, I did it one more time. It worked and I've been doing well ever since.
It's nice to know that should I slip again (or completely fall), that I can do it again whenever I need to get back on track!