Why these dates (Friday after Thanksgiving in North America, the following Saturday in Europe and Asia)?
In many countries, this weekend is the beginning of the Christmas shopping season. In North America, where BND started, the Friday after Thanksgiving is famous for its wild shopping frenzy. The media always report on the sales numbers and consumer behavior on this day (the crazier the rush the more enthusiastic the reporters). In Europe and Asia we celebrate it the following Saturday, because sales are higher on that day.