You can have fresh date codes (several months anyway) if you ask. I worked with a huge company and asked when they would be ordering stock in my size. They were pleased to do it as none of their huge customers care. So basically your not really competing with anyone for the best date codes.
Usually you are doing good if the tires are less than 6 months old, especially if you are buying tires in a common size. If you want to accept older tires, ask for a discount to make up for the time lost. It doesn't hurt to ask and sometimes the dealer will give it to you to make the sale. If your trade-in tires are recappable, you may also ask how much they will give you as a carcass credit. Here is what one place pays: tire values