'tis the season for Christmas markets to open up in different parts of Paris. Unlike in the United States where there is a definite date when the Christmas season begins - on the day after Thanksgiving, the holiday ambiance begins to take over this romantic city by mid November in some areas, and later in others. A Christmas market is, usually, a street market related to the celebration of Christmas during the season of Advent - the four weeks before Christmas. Its origins can be traced to…