Billboard Year-End charts are a cumulative measure of a single or album's performance in the United States, based upon the Billboard magazine charts during any given chart year. Billboard's "chart year" runs from the first Billboard "week" of December to the final week in November, but because the Billboard week is dated in advance of publication, the last calendar week for which sales are counted is usually the third week in November. This altered calendar allows for Billboard to calculate year-end charts and release them in time for its final print issue in the last week of December.