PATEK PHILIPPE PERPETUAL CALENDAR GRAND COMPLICATIONS Ref. 5159J-001
Patek Philippe Perpetual Calendar with 38 mm yellow gold material. Sapphire-crystal case back protected by a hinged dust cover. Opaline-white dial, hand-guilloched center dial. Matte chocolate brown leather. Fold-over clasp. Self-winding mechanical movement. Caliber 324 S QR. Day, month, leap year in apertures. Sweep seconds hand. Water resistant to 30 m.
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.