Christmas Day looms just two days away, and, with the month-long build up of December nearly over, one could see that day as the destination festivities have been building towards. The last few days have also likely been filled with familiar songs for the holidays, for timeless religious hymns to classic radio jingles. However, in the context of our modern celebration, one carol in particular might ring slightly odd. Though many expect plentiful gifts from their true love this year, itâs not too common for Christmas celebrations to be a 12-day affair. So, when and what, then, are these 12 days? And where does this popular song originate?