To avoid the need for manual adjustment on a mechanical timepiece to account for leap years, in 1795 A.-L. Breguet perfected the perpetual calendar, known in French as the Quantième, to display the exact date while taking into account the variable length of the months and the leap year cycle.

With the Classique 7327, Breguet guarantees this precision by installing the movement with a mechanical "memory" of four years, or 1,461 days.

With its thickness of 4.5 mm, the 502.3.P movement in the Classique Quantième Perpétuel 7327remains one of Breguet’s slimmest, while still delivering high performance.