Display mechanism (10) for a timepiece (1000), with a leap year display integrated in a month display, comprising a control mechanism (3) that drives, once per month, about an axis (D), a month display wheel set (2) arranged underneath a dial (1), having a month window (1C) in a quadrant allowing the display of only one quarter of the month display wheel set (2), which completes one revolution in four years, and bears, on an angular sector of 90°, at least one characteristic leap year marking, and either carries indices, each arranged to indicate one month on a static month scale of the dial (1), or equidistant month markings, wherein one of the month markings is pointed to by a fixed mark of the dial (1).