"where have you been your whole life"
It's the shopping day after Thanksgiving in the US.
Taken from another site:
"According to Jane M. VonBergen, the author of the article, "Black Friday: Early To Bed, Early To Buys," says that the name was "traditionally the day that retailers began making a profit, noted in black ink, for the year (A1)." For many Americans, going Christmas shopping on Black Friday has become a tradition and it is exciting to them."