So do you know what are the real Twelve Days of Christmas? They are the twelve days from Christmas Day to the eve of the Epiphany (Little Christmas or Los Reyes if you’re Latin). Each of the days either celebrates a saint or has a particular feast attached to it. You can read more about that here: https://www.whychristmas.com/customs/12daysofchristmas.shtml
The last night of the 12 Days is Twelfth Night and is the Eve of the Epiphany or Los Reyes. In my house we still celebrate the arrival of the Three Wise Men (or the Three Kings) and have a celebratory meal and exchange small gifts.
As for the song about the Twelve Days of Christmas, you know the one with the Partidge in Pear Tree, guess how much all those gifts would cost you this year! According to Business Insider, nearly $35,000! (see http://read.bi/2Dff58Q).