Patek Philippe is adding a brand new perpetual calendar with an original in-line display to its rich range of calendar watches. The day, date and month appear in a large single aperture at 12 o'clock. So as to combine originality, legibility and reliability, the watch design engineers have developed the new self-winding movement 31-260 PS QL with an additional in line display module, for which three patent applications have been filed. This highly sophisticated new caliber is housed in an elegant platinum case framing a vertical satin finished blue dial with a black gradient rim. Ref. 5236