Patek Philippe has chosen a classic and sober dial layout for its new Perpetual Calendar Reference 5320G, not unlike that of the model launched in 1941: a double aperture for day and month at 12 o'Clock, and at 6 o'clock a subsidiary dial for the date by hand and moon phases. Day/night and leap year are indicated by discreet round openings in the cream dial. The automatic 324 SQ calibre stands out for its perpetual calendar module, developed for these four aperture displays. The moon phase requires an adjustment of a single day every 122 years. Adding to this watch's appeal is the "retro-modernistic" case, in white gold, whose three-tier lugs cast back to the 1950s and Reference 2405.