The 1920s (pronounced "nineteen-twenties", commonly abbreviated as the "Twenties") was a decade of the Gregorian calendar that began on January 1, 1920 and ended on December 31, 1929. In North America, it is frequently referred to as the "Roaring Twenties" or the "Jazz Age", while in Europe the period is sometimes referred to as the "Golden Age Twenties" because of the economic boom following World War I.