A lot of national food "holidays" (seriously, who makes these holidays?) are, in a word, lame. Booze holidays, though? Booze is fun. A celebratory "reason" to drink is exceptionally fun. Therefore, booze holidays are especially exceptionally fun.
National Tequila Day is Sunday. And as the holiday festivities rulebook states, celebration for any given holiday can start within a two-day period prior to said holiday (i.e. Friday, Saturday, and Sunday). Also, we totally just made up this rule, but it's still valid.