Even though Barcelona's Christmas lights have been up since the end of November, Christmas-time in the city really begins on December 6th.
December 6th marks the rather prosaic Constitution Day in Spain, a national holiday commemorating the signing of the Spanish Constitution in 1978, three years following the end of Franco's dictatorship. Practically speaking, it's the last long weekend before Christmas. If the 6th happens to fall on a Tuesday or Thursday, todo el mundo hace el puente--that is, everyone takes a vacation day on the Monday or Friday to make it a four day weekend...five day if the holiday falls on the Wednesday. As a result, the day is sometimes referred to as El Puente de la Constitución.
Most everywhere else in Europe, December 6th is St. Nicholas' Day. St. Nicholas--patron saint of children, students, sailors, archers, merchants and pawnbrokers--is the less commercialized version of the modern day Santa Claus.
Legend has it that St. Nicholas was an infamous anonymous present giver. Preferring to eschew gift giving glory, he deposited his parcels after nightfall, long after prying little eyes were fast asleep. One story has it that he took pity on a poor farmer who wasn't able to afford dowries for his three nubile daughters. On three consecutive nights, St. Nicholas crept up to the family home and tossed gold into stockings that the sisters had hung out to dry thereby funding their dowries and saving the maids from a certain fate of prostitution--not to mention giving a whole other meaning to his signature "Ho! Ho! Ho!".
St. Nicholas is often depicted with three sacks or balls of gold in a nod to the legend. In certain countries, the balls of gold have been transformed into oranges in the popular imagination leading to the tradition of giving oranges as gifts on December 6th. Conveniently, it's when oranges happen to be in season.
While St. Nicholas' Day is not particularly celebrated in Spain, the Dutch seem to believe that Sinterklaas (the Dutch version of St. Nicholas) hails from these parts. Dutch legend has it that after Sinterklaas gives presents to all the good little children, he packs up all the bad little children in his empty sacks and takes them back to his Spanish lair. Presumably to work in his sweatshops...I mean workshops.
Ho! Ho! Ho!