I stopped in my store and asked the guy at the door, he asked someone else and they told me that Ultra and Maxx would be available on the 20th and the other one (Mini) would be available a week later. So the people in my store knew. But to play devil's advocate for a minute, they probably have new phones coming out every week* and just because we've been tracking this phone for a month and drooling over it doesn't mean it's that big of a deal to them. The release date will come and go with little fanfare and they'll have another phone come out a few days later that someone else has been dying to get their hands on for weeks. I mean, after he told me what day it came out, should I have asked him if it would be available right away when they opened or if I should wait a few hours? A fair question, but not something 'random employee' should be expected to know, IMHO.
The only phone these guys probably have the release time memorized, down to the hour, is the iPhone.
*Yes, I know there's lots of dinky/nothing/cheap/free phones, but there's these three, Moto X, the new HTC, the next Note and probably some others all coming out soon, they can't be expected to have all the dates memorized.