Tea generally has a two year shelf life from wholesaler to retailer extend the teas shelf life
Put your tea immediately in tea cannisters you can buy at SKS bottles, or Ebottles, Make sure you purchase food grade metal canisters. You will extend your tea shelf life.
Most large wholesalers now “flush” with inert gas and then vacuum pack in multi-layer high-density bags. As long as the tea remains packaged this way, the shelf life can be up to 20 years.
I think vendors/wholesalers/suppliers/manufacturers should all carry the harvest date information of the tea. Shelf life is a knowledge which tea drinkers have many ways to learn, not necessarily from the vendor. But without harvest date information, shelf life doesn’t mean much.