Goddess locs and fauxlocs can generally last 2-5 months depending on the person. And the type of install selected. I personally do not recommend keeping your locs in longer then that.
I usually don't recommend keeping a protective style in any longer than 12 weeks. But I have known clients and comrades to go longer. The reason I recommend a 3- 4 month max is to avoid dreading and breakage however with proper care they can last long periods of time.