The Patek Philippe Perpetual Calendar Ref. 3945 was introduced in 1985 and produced through 1998 as a bracelet alternative to the 3940, another icon in the brands catalogue. These watches feature a classically designed perpetual calendar dial with the day and 24 hour subdial at 9 oclock, a moonphase and date display at 6 oclock and month and leap year indicator at 3 oclock. The example offered here is a beautiful yellow gold variation with a 18cm bracelet and second series dial. This watch comes with an Extract from the Archive noting a production year of 1990 and sale in February of 1991.