Actually, that date is usually used as the expiration date for your license, so you get a brand-spankin-new license when you turn 21. Unfortunately, since the license is expired, it is no longer valid, and a vendor can not legally sell without a valid license. So say you ID a 40ish female to flatter her, and her license is expired. Technically, you can not sell to her. This is primarily designed so that I can't give my expired license to my younger brother or facially-similar friend to use after I turn 21.