The day's name originated in Philadelphia, where it originally was used to describe the heavy and disruptive pedestrian and vehicle traffic which would occur on the day after Thanksgiving.[4][5] Use of the term started before 1961 and began to see broader use outside Philadelphia around 1975. Later an alternative explanation began to be offered: that "Black Friday" indicates the point at which retailers begin to turn a profit, or are "in the black".[4][6]