I'm IN the tire business.. and while there is a limit on how old a tire we can sell, 12 months is not uncommon, especially when it's a slow-moving size in a second-tier product.
Seems like every couple of years, the auto industry become enamored with a new size/profile tire, so what WAS a popular size just a few years ago, may actually be obsolete today. Especially good for this is our beloved Ford; an F150 pickup, depending on drive-line, trim and GVW, may have SEVEN different size tires on it from the factory. So we stock the one or two most popular, then get griped at by customers walking out when we don't have one of the less popular options. Hey, we didn't spec it.. Ford did, so go b!tch at them.
Not that I try to stuff a five or six year old tire down anyone's throat, but at the store level, we don't have any choice on how new or old a tire is that we get from the warehouse. Warehouses use FIFO inventory, so if it's a dud, you're going to get a ripe one. And I can't return them simply because they're not 'fresh" enough for a customer. Tires are run off in batches, sold in batches, ordered in batches. So on a B or C mover, a year old might be as new as you're going to find because if you want to wait for the next production run, it might be two months before there's enough orders to justify putting the molds in the ovens. Then it's going to be another six to eight weeks before the tire gets to the store..
So there's two sides to every story.