Since Audemars Piguet was founded more than 140 years ago, it has continuously studied breakthroughs in the field of calendar watch creation. If all time measurement tools are regarded as the expression and extension of astronomy, then the calendar mechanism is a complex function of witnessing history, which perfectly reflects the close relationship between astronomical observations and the evolution of calendars and timepieces. The Jura Valley is uniquely positioned to enjoy the benefits of observing celestial bodies and admiring wonders. Whether it is past or present, it is always an ideal place for watchmaking craftsmen who draw inspiration from natural landscapes. Making the Leap is the opening book in a series of articles delving into Audemars Piguet’s twentieth century full calendar and perpetual calendar watches.
   Audemars Piguet Perpetual Calendar and Full Calendar Watches are exceptional rare timepieces, embodying wonderful aesthetics and unparalleled quality, and have long been recognized and respected by collectors. Perpetual calendar pocket watches have been released since the company was founded in 1875. According to records in the archives, the first Audemars Piguet watch with moon phase display was launched in 1924, while the first perpetual calendar watch was produced in 1950 and delivered to customers in the same year.
   In the first half of the twentieth century, only a few watch factories like Morningstar knew how to make perpetual calendar watches. During this period, many companies, including Audemars Piguet, were well acquainted with the production of full-calendar watches with moon phase displays; however, during the same period, the perpetual calendar device was still recognized by most watch manufacturers as highly complex The elusive micromachine was one of the most difficult challenges facing the traditional watchmaking industry at the time. It is believed that the first perpetual calendar watch was made by Patek Philippe in 1925. In 1941, this watch factory mass-produced the first perpetual calendar watch. Although these timepieces are important works worthy of collection, they may lack the leap year display function of previous perpetual calendar pocket watches. The leap year display is a key feature of the perpetual calendar watch, because it can accurately and clearly define the calendar mechanism in the vast astronomical cycle.
Archive photo 1012, model 5516

   According to recent research, at least three perpetual calendar watches were made by Audemars Piguet in the early 1950s; however, these three watches also lacked leap year display. These watches were made just before Audemars Piguet began to implement the numbering record, so these new perpetual calendar watches were immediately numbered at 5516.
   In 1955, Audemars Piguet took the lead in the production of perpetual calendar watches featuring the world’s first astronomical leap year display. A total of only 9 highly acclaimed classic watches have been launched since the 5555 model. In addition to the carefully crafted 36.5 mm case, these timepieces are also uniquely matched with a beautiful and meticulous dial. Following the upsurge of this creative and addictive rare watch, in this series of watches, the shape of the dial has been renewed.Although the interpretation of some details seems insignificant, it makes Several of these watches have been renewed and become unique timepieces.
Archive photo 1048, model 5516

   The initial series of 5516 models with leap year display was put into production in 1955, and only three were issued. Their moon-phase opening at 12 o’clock and the 48-month sub-dial at 6 o’clock, with the leap year display function, are two features that can be recognized at a glance. The months of these timepieces are divided into four-sided sectors to show a four-year cycle, and are clearly marked with the first year-second year-third year-fourth year. In order to easily read and improve the functionality of the watch, 12 months of the year are displayed with a sub-dial at 3 o’clock, so it is more eye-catching and clear. The dial displays each month with a three-letter abbreviation. These three watches were made in 1955 and formally delivered to customers in 1959.
   The last version of the model 5516 produced a total of six pieces, again using the traditional moon phase display at 6 o’clock. The leap year display is located at 12 o’clock, making it easier to identify. These four watches that have received the attention of the market have established a significant position for the leap year cycle display. Only one watch follows the 48-month leap year display design. Because the fonts are too small to read, their symbolic functions are greater than practical functions.
5516’s Profile Photo

   Six versions of this timepiece were produced in 1957 and sold between 1963 and 1969. Two of these watches belong to the Audemars Piguet Antiquities Department, while the other one has the retailer Tiffany & Co. logo on the dial.
   In addition to being the first series-produced perpetual calendar watch with a leap year display on the global dial, model number 5516 is a fine example of the existing établissage watchmaking system of the twentieth century. This mode of production was born in the Jura Valley in the eighteenth century, relying on a cooperative enterprise consisting of hundreds of small professional independent workshops. Assemblers (établisseur) coordinate the work of watchmaking craftsmen to integrate production. They are not only responsible for the assembly, adjustment and casing of the watch, but also for the sales of the watch.
Archive photo 1774, model 5516

   The assembly and production of these 12 5516 models of hairsprings, pallet forks, precious stones, screws, balance wheels and other parts are carried out by a number of small companies located in the Jura Valley, which provide parts for Audemars Piguet. The broken parts of the movement (base plate and bridge plate) are produced by Valjoux, and the ‘cadrature’ mechanism of the calendar function is made by independent craftsman Alfred Aubert. Audemars Piguet’s watchmaking technologists manage these operations and assemble and adjust movement parts. Finally, they decorate and case the watch, sell timepieces through the retailer’s network, or establish partnerships with other globally renowned companies.
   The model number 5516 is a very good timepiece in the history of Audemars Piguet. It is rooted in the balance and beauty of innovation and tradition. This watch draws a blueprint for the horological world full of development prospects, because it is the world’s first perpetual calendar watch to display leap years on the dial, and the diameter of 36.5 millimeters was a relatively large-scale design at the time of release. However, it also looks back deeply in the past, because its extraordinary production is the result of the 18th century Jura Valley établissage watchmaking system. In other words, it was a system that was proud of Jules Louis Audemars and Edward Auguste Piguet since the founding of Audemars Piguet in 1875.