In order to accommodate months with 31, 30 and 28 days, and february 29 in leap years, a movement must have a mechanical “memory” of four years – or 1,461 days. This function requires a highly sophisticated mechanism, based on a complex system of levers and cams pivoting around their axes. This is a domain in which Patek Philippe has repeatedly leveraged its long-standing competence.
Ultra-thin mechanical self-winding movement. Caliber 240 Q. Perpetual calendar. Moon phases. Day, date, month, leap year and 24-hour indication by hands. Bezel set with 68 diamonds (~0.68 ct). Prong buckle set with 27 diamonds (~0.2 ct). Dial: Silvery-white opaline, gold applied hour markers. Straps: shiny alligator with square scales, hand-stitched, mink gray (originally fitted) and royal purple (additional strap). Prong buckle set with 27 diamonds (~0.2 ct). Case: rose gold. Interchangeable full back and sapphire-crystal case back. Water resistant to 30 m. Case diameter: 35.1 mm. Height: 8.7 mm.