Let's see, it's 11am and it's 75 degrees currently in my basement office on the east side of the house on what will be the last of a 90+ degree week. I plan to store it in the closet under the stairs, a tad more interior to the house. Will I be able to calculate accurately when it begins to degrade? It sounds like I might be guessing towards the end of the supply. For that matter, what is the generic WalM bleach measuring at right now after being manufactured, shipped, stored, shipped again, stored and put on the shelf? Hmmm.