.Patek Philippe Platinum Perpetual Calendar ref. 3940P-011 – very rare and highly collectible important watch

Case: massive, polished, satined, concave bezel, sapphire crystal. 

Patek Philippe introduced the reference 3940 Perpetual Calendar in 1985, alongside the reference 3970 (Perpetual Calendar Chronograph). These two complex watches were launched during the „Quartz Crisis,” a period when many brands were focused on the threat posed by changing trends. The reference 3940 was produced from 1985 to 2007 and has since become a „Grail Watch” for many collectors. Initially, it was available exclusively in yellow gold (in limited numbers for Beyer), and later in rose gold, white gold, and platinum.

During the „Quartz Crisis,” major Swiss companies were not creating complicated timepieces, as the industry’s decline meant there was no spare capital for innovative investments. They had just enough resources to maintain their remaining market share. Introducing both a perpetual calendar and a perpetual calendar chronograph (ref. 3970) simultaneously was a bold move by Patek Philippe. The timing was perfect, as people were beginning to appreciate the value of mechanical watches again. This was partly because observing a mechanical watch and its movement is a very tangible experience—you can see how it works and how everything is connected, unlike a quartz watch powered by an incomprehensible chip. Perhaps it ties into a universal admiration for craftsmanship, but regardless of the reason, this watch is a significant foundation for Patek Philippe’s success today despite the challenges faced. It’s no coincidence that Philippe Stern himself, despite having access to any Patek Philippe watch he desired, chose to wear a 3940 every day.

Apart from the historical significance, the 3940 itself is a marvel in both design and movement. It houses the beautifully finished in-house perpetual calendar caliber 240 Q, featuring an integrated off-center micro rotor, allowing this incredibly complicated watch to remain astonishingly slim at just 9mm thick. To ensure such a small rotor could power the watch, it was made from 22k gold, with the additional weight providing more force to wind the watch.

Creating a perpetual calendar is a formidable task, involving 275 different parts. As a testament to its complexity, at the time of its release, only two people in the manufacture were permitted to assemble such intricate watches. While a perpetual calendar may not have the same status as a chronograph, despite being more challenging to produce, due to its lack of tactile interaction, the skill required to create a watch with a memory of four years, accounting for the days in each month including February and leap years, is immense. Adding a moon phase and 24-hour clock further underscores the complexity of this remarkable timepiece.