BACK IN TIME
What is perhaps even more amazing about the perpetual calendar watch, however, is that it was invented more than two centuries ago in 1762, just ten years after Benjamin Franklin’s infamous electricity experiments. It was engineered by an Englishman by the name of Thomas Mudge, who was one of country’s most famous watchmakers of the era. Sadly, however, the complication did not seem to catch on with the watch-wearing public, and the complication languished for the next century. It was only in 1864 that Patek Philippe began to build perpetual calendars, and the story of the complication began anew. While the brand was not the originator of the complication, it is still considered one of its early adopters and was granted a patent for its perpetual calendar mechanism in 1889, which allowed the date, day, month, and moonphase to jump instantaneously and simultaneously. The complication made its way into various pocket watches, but it wasn’t until 1925 that Patek Philippe created the first-ever perpetual calendar wristwatch. Surprisingly, that watch—with a reference number of 97’975, and whose movement was named the calibre 12’’’—was never meant to be a wristwatch in the first place. It began life as a ladies’ pendant watch in 1898, and its small size meant that it could be repurposed into a men’s wristwatch, one that would make horological history. So how exactly does a perpetual calendar mechanism work? Every perpetual calendar mechanism has a main lever that is connected to wheels that control every day, date, month, and year indication. Each passing second is factored in, with 60sec adding up to a minute, 60min to an hour, and 24 hours into a day. For Patek Philippe, there are two different cams: a 12-month cam that finishes one revolution per year, and a 48-month cam that makes a full revolution every four years. Each round cam has notches of different “depths” that allow the movement to tell how many days there are in a particular month. For 12-month cam systems, each revolution of the cam feeds into a leap year wheel that turns to indicate the passage of a year. Four such indications will mean that it is time for a leap year to occur— in most cases anyway. Since the launch of the calibre 12’’’ in 1925, Patek Philippe has made many landmark perpetual calendars that have demonstrated its watchmaking expertise. In 1941, the first serially produced perpetual calendar chronograph was launched, and would remain the only iteration of this complication for nearly half a century. Then, in 1962, it released the first self-winding perpetual calendar wristwatch. Subsequently, Patek
New watches that take on the look of old, vintage ones have been a trend for the past few years, but the self-referential nature of Ref 5320G ensures that it still looks like the quintessential Patek Philippe perpetual calendar watch