Richard, Some of the data came from Clorox's FAQ section. They mentioned that the bleach is actually formulated at higher than advertised strength, so that as it "ages" it should (if stored properly) be at it's advertised strength up to 6 months. It also mentions something about making stronger formulations in the summer months than they do in the winter months to counter-act high summer temp degradation.

I'm not posting with any intention of being an "expert" just passing on some info. I thought the shelf life was like 30 days....