Traditionally, until Christmas Eve (December 24) Christmas tree will stand decoration and 12 night (January 6) removed. Advance and pushed back the date is considered to be unlucky.
However, modern Christmas shopping season that most stores set up Christmas at the end of October. (In the United Kingdom Selfridge's Christmas open in early September, the Christmas tree).
Most United States family, its habit of Thanksgiving (fourth Thursday of November) was erected immediately after Christmas until after the new year. Some United States home until December the second large put up Christmas trees, Christmas tree stand on January 6 (Epiphany).
In Germany, traditional Christmas tree December 24 state, but some 1-2 weeks in advance to set up.
In Australia, it is one week before the school summer holidays; but exceptions to South Australia, where most of the early November (after the Adelaide Credit Union Christmas pageant) was set up.