Trafalgar Square Authority in conjunction with the charity Unicef, who began ticketing the event to control crowd numbers. A Christmas ceremony has been held in the square every year since 1947. A Norway spruce (or sometimes a fir) is presented by Norway's capital city, Oslo as London's Christmas tree, a token of gratitude for Britain's support during World War II. (Besides war-time support, Norway's Prince Olav and the country's government lived in exile in London throughout the war.) The Christmas tree is decorated with lights that are switched on at a seasonal ceremony. It is usually held twelve days before Christmas Day.
Christmas tree (31 October). In Canada many families wait until after Remembrance Day, as to show respect to fallen soldiers. Some households do not put up the tree until the second week of December, and leave it up until 6 January (Epiphany). In Germany, traditionally the tree is put up on 24 December and taken down on 7 January, though many start one or two weeks earlier, and in Roman Catholic homes the tree may be kept until February 2 (Candlemas). In Italy, Ireland and Argentina, along with many countries in Latin America, the Christmas tree is put up on 8 December