I can't find the chart I had, but I will look for it this weekend and share it if someone does not post it sooner. The gist of it is the hotter it is/more sunlight on it the quicker it degrades. Keep it out of high temperature areas when storing your bulk and you should never have any issues as long as your using it.
Someone please correct me if I am wrong. I was always under the assumption that chlorine bleach began to degrade after about 30 days. I know that Clorox say it is good for like 6 months. As it degrades it does not mean that it is not effective, just not as strong. I also know that when it begins to degrade it loses its ph level and that by adding some amount of sodium hydroxide you can raise the ph level back up. I have done this with wood usually with bleach leftover from the previous year. Never tried it with house siding, nor would I.
"All bleach decomposition is dependant on temperature. For any given temperature, the higher the strength, the faster it decomposes and the higher the level of oxygen and chlorate formation. In summary, for every 10° C increase in storage temperature, the sodium hypochlorite will decompose at an increased rate factor of approximately 3.5." From Powellfab. My understanding you would be dead on Everett except it is degrading constantly just things like temperature or organic matter/the higher strength SH that we use make it degrade much faster then say clorox.