there are ways to detect the date by the coding found on Ilfords box; however, that code is not well known. At one time, one could get in touch with their website site moderator and he would translation that informtion.
Forte has a coding system with the sku number. Their Forte Polywarmtone (orginal version) has a very long shelve life . I have several boxes that are 6 and 7 years old that are still not showing any fog. At one time, their tech support indicated that the paper would just get a bit warmer over time.
Oriental Seagull has changed owners and packaging over the years and if you know it's history you can ball park the changes. The orginal Oriental holds up extremely well. I was given some and since then that has to be over 20 years old and is still printing well with no signs of fogging.
Agfa, just changed packing(with very strange phots, IMHO) but their standard orange box has been around for ever (or at least it seems that way).
I don't use Kodak products so don't have a clue.