Shelf life and product code dating

Titebond in all the different flavors is my favorite family of wood glues. Franklin gives a standard shelf life of 1 year for all their glues for an unopened container. Keeping air out of the container helps, but still begs the question: When does that timer start? When was that bottle of glue made / when does that year start? That question is equally applicable to any finishing product.
It basically comes down to lot numbers. Lot numbers are generally stamped in easily smudged numbers on individual bottles, but if not there, then is printed on the cardboard box the bottles come in - thank goodness many stores only unbox a few bottles at a time and the rest stays easy to date from their birth certificate on the box. Quoted from www.titebond.com:
"How do I read the lot numbers?
The letter "A" is always used at the beginning of a Franklin International lot number. The second digit corresponds to the last number of the year. Digits 3 & 4 correspond to the months of the year. The 5th and 6th digits correspond to the day of the month the product was made. Lastly, digits 7 through 10 are batch numbers. Therefore, a Titebond product with the lot number of A906010045 was manufactured on June 1, 2009."
It turns out that there are more ways of coding Titebond Lot numbers than the above, as talked about here.
So, it comes down to tracking down (and deciphering) what the lot numbers mean to determine product age - marking a products "born on" date isn't as useful as marking when it goes bad, which I recommend that you do "in the clear" with a Black indelible marker! Especially if you have to get the "born on" date from a box that stays in the store. If you can't be bothered, buy from some place that does brisk business and date from when you buy the bottle. Otherwise, beware of that dusty bottle purchased from a Mom and Pop - sorry, I like to support Mom and Pop operations, but your project depends on its life based on the glues and finishes it is made with.