Date codes are only one factor of many when considering a tire's quality/life expectancy. Many other factors such as temperature where stored, how long have they been stored, have they been sitting in sunlight, have they been in a humid shed, have they been off the wheel, on the wheel, sitting with water in them, etc. This is why you check a tires physical condition (hardness, signs of cracking, loss of shape, odd coloring, etc) I just had a bike on the lift this weekend that had tires with a 2009 date code. Guess what, they looked perfectly fine and they guy was railing corners on a Goldwing with them. I understand you're trying to help, but this topic has been beat to death lately. People need to worry less about date codes and more about tire pressure. That is the #1 cause for premature tire wear or poor handling.