When did the 2014 MBA come out?

I received my custom ordered MBA 13 in April 2014. It's a mid-2013 model. Apple tried to explain to me why it wasn't an early 2014, but I feel the explanation was lacking. I'm not sure if I got one from old inventory that just happened to match the specs I ordered. If you folks could give me some feedback on this, it may make me feel better. By the way, I love the computer!