Second Series 3940J Patek Philippe Perpetual Calendar

Patek didn’t make the first neo-vintage era perpetual calendar, in fact they were late, a full 7 years. But they might’ve done it best. These are fighting words, I know, but to me the earlier 5548 and 43031 are scaled up, modernized versions of first AP 5516, incredible in their own right and responsible for the genre. But the 3940 feels like a scaled down, wrist-format version of nirvana; divinely inspired. The dual-information subdials allowing a hard signature at 12, 2.53mm thin micro-rotor 240Q with its artfully separated bridges, and sensual case design. But don’t listen to what I say, listen to god for Patek, John Reardon, who stated that, ‘for the price, there is arguably no other watch that encapsulates all that defines Patek Philippe’. It might just be the sexiest perpetual calendar ever.


The 3940 ran from that tenuous introduction in 1985 to an official discontinuation in 2007 as a legend. The immensely impressive complicated reference was a statement: mechanical watchmaking is here to stay. Philippe Stern chose a 3940 as his personal watch not unthinkingly. He had created an ultra-thin perpetual calendar that would not need to be adjusted for over 100 years from the ashes. The micro-rotor calibre 240Q was just 2.53mm tall while retaining chronometric specification and a 48 hour power reserve. There was a lot of engineering that went into that. As an example, to maintain that specification and reserve, friction needed reducing. Patek eliminated the rotor inverter system and engineered a new gear tooth shape while polishing it differently to avoid frictional losses. The movement is still in production today, decades on.


This second series is distinguished from the first largely by its subdials, which have bevelled edges that give a larger overall impression. The signature at 12 is also slightly larger and the grave accent of Geneve disappeared. Latter third series are easily distinguished by the sigma signatures, which fall in line with the minute track instead of outside, not this. This was also where the display back was introduced as an option. It is estimated that 3500 second series were produced, with best estimates of overall 3940 production somewhere between 7000 and 8000 examples, or about 350 per year.

It’s kind of like another 80s icon, A-Ha. They didn’t do synth-pop first, The Human League, Kraftwek, and Duran Duran were jamming on Yamaha DX7s long before A-Ha. But when you think synth-pop, you start singing Take On Me. Take this 3940 on. It’ll be gone. In a day or two. I’m glad I’m writing and not singing, my voice always breaks before ‘two’.

This example has a full case, deep engravings, and light even wear with maybe what I’d call the slightest touch on its lower right hand lug worth noting. The dial appears flawless. It comes with its original box from a well-regarded Shanghai retailer.

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