Patek Philippe Perpetual Calendar 3rd Series With Papers (Ref. 3940)

History and Significance

The reference 3940 is widely considered one of the most important modern Patek Philippe references ever produced. Introduced in the mid-1980s, it marked a major turning point for the brand and helped reestablish complicated mechanical watchmaking during a period when much of the industry was still recovering from the quartz crisis.

Powered by the ultra-thin caliber 240 Q perpetual calendar movement, the 3940 combined remarkable technical complexity with restrained proportions and everyday wearability. Unlike many perpetual calendars that feel oversized or overly formal, the 3940 remains elegant and balanced on the wrist. The thin automatic movement allowed Patek Philippe to create a watch that slips effortlessly under a cuff while still offering one of the most respected perpetual calendar layouts ever designed.

Collectors have long appreciated the reference for its subtlety. Nothing about the watch feels exaggerated. The recessed subdials, leaf hands, applied markers, and compact case proportions all work together in a way that feels distinctly Patek Philippe. It is one of the clearest examples of complicated watchmaking executed with restraint rather than excess.

Writer’s Thoughts

The 3940 is one of those watches that becomes more impressive the longer you own it.

A lot of perpetual calendars feel like collector pieces first and wearable watches second. The 3940 somehow manages to be both. It wears incredibly well, feels thin and refined on the wrist, and works in almost any setting without feeling overly formal. Also, the strap choice completely changes the watch's personality. On black alligator with the gold deployant, it feels very traditional and elegant with tailoring. Put it on a warm calfskin strap with denim and a sweater, and suddenly the watch feels much more relaxed and personal. Very few perpetual calendars transition that naturally.

Our Promise

Every watch is thoroughly vetted, carefully described with complete transparency, and guaranteed authentic. Each piece is offered in honest condition, ensuring collectors receive a timepiece that reflects both originality and integrity.

Brand: Patek Philippe

Model: Perpetual Calendar (Ref. 3940)

Year: circa 1990s

Case Material: Yellow gold

Case Size: 36mm

Bezel: Smooth yellow gold bezel

Dial: Silver dial with perpetual calendar displays and moonphase

Movement: Automatic

Strap/Bracelet: Original alligator strap

Buckle/Clasp: Original Patek Philippe gold deployant clasp

Contents: Certificate of Origin papers and product literature