Patek Philippe 3940 Perpetual Calendar Series Guide

err_404 · 2019-12-02T04:14:57Z

Explore the Patek Philippe 3940 perpetual calendar. Learn about its different series, dial variations, movement upgrades, and collector insights.

err_404

WPS member · Patek Philippe forum

22 replies6154 views2 photos

Err_404 initiates a detailed inquiry into the Patek Philippe Ref. 3940, seeking to unravel the nuances between its various series. This post serves as a valuable resource for collectors aiming to understand the subtle yet significant distinctions that define this perpetual calendar reference.

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Dear all,

recently, I have seen many posts of the Patek 3940 on the forum. My interest for this reference is growing and I am looking for information about this beautiful model.

According to what I have read so far, it seems that many series were produced.

I have quickly searched on the Internet and I have not found any good articles presenting the different series and highlighting their differences. I have noticed this interesting article which talked about the history of Patek Philippe's perpetual calendar. However, it does not describe the different series of the 3940.

I would like to know if you are aware of any good article that would talk about the specificities of each serie of the 3940 or, if possible, if you can tell me how many series were produced and what are the main differences.

As a subsidiary question, I have noticed that some versions have half of a circle of the indicator on the left in yellow. Is it normal or does it come with time?

Thank you very much in advance

Have a good day

Rodolphe

Credit photo: https://www.acollectedman.com/

Credit photo: lascases on Watchprosite ( www.watchprosite.com )

About the Patek Philippe Grand Complications Ref. 3940

The Patek Philippe Reference 3940 is a perpetual calendar wristwatch that was introduced in 1985, succeeding the Reference 3450. It is notable for its relatively slim profile and the integration of a perpetual calendar complication in a refined case. This reference became a cornerstone of Patek Philippe's complicated watch offerings for nearly two decades, establishing a design language for subsequent perpetual calendar models. It represents a significant period in the brand's modern history of complicated timepieces.

The watch features a 36mm case, typically crafted from yellow gold, rose gold, white gold, or platinum. It houses the self-winding Caliber 240 Q movement, which is known for its micro-rotor construction, contributing to the movement's thinness and allowing for a slimmer case profile. The movement provides a power reserve of approximately 48 hours. The dial is protected by a sapphire crystal, often accompanied by an interchangeable solid case back and a sapphire display back.

Reference 3940 is highly regarded by collectors for its classic proportions and the enduring appeal of its perpetual calendar display, which includes day, date, month, leap year cycle, and moon phases. It was produced in several series, with subtle variations in dial layout and typography, making early series examples particularly sought after. The reference is considered a benchmark for perpetual calendar watches and remains a significant piece for those appreciating traditional horological complications.

Specifications

Caliber: 240 Q

Case: Yellow Gold, Rose Gold, White Gold, Platinum

Diameter: 36mm

Dial: Silver, White, Opaline

Crystal: Sapphire

Key Points from the Discussion

The Patek Philippe 3940 was produced in multiple series, with key differences in dial configuration, particularly the recession of the day/month rings and the design of the leap year subdial. Early series often had a more prominent day/night indicator shading.
The first series of the 3940 comprised approximately 700 copies, with movement numbers ranging from 770,000 to 770,700. The third series began around 1995 with event numbers starting from 3,000,000.
The leap year quadrants on the first series were typically arranged as 4,1,2,3, while later series adopted a 1,2,3,4 configuration to align with the quarters of the year. Not all series feature day/night shading on the 24-hour indicator, and its visibility can vary due to patina.
Identifying the exact series can be challenging due to potential mixing of early series dials with later series watches, especially during transition years. Checking serial numbers is the most reliable method for definitive identification.
Subtle font differences in the third series, along with variations in the placement of the 'sigma Swiss sigma' relative to the outer minute track dots, are additional distinguishing features. Mechanical upgrades were also implemented across series, though these would typically be corrected during routine servicing.
The yellowing of the day/night indicator on some 3940s is a natural phenomenon, with variations in how pronounced the shading appears due to aging and inherent dial differences, rather than being a defect.

The Discussion

cbb in honor of Chamnong Bhirombhakdi

Dec 2, 2019

Half Circle

I believe is Platinum

err_404

Dec 2, 2019

Thank you very much for your reply Cbb.

Actually, I have noticed that some gold versions also have it.

amanico

Dec 2, 2019

Half circle for day / night time. [nt]

err_404

Dec 2, 2019

Thanks Nico. It makes perfect sense.

It seems that some series have it and some do not. I wonder if it was done for the first series or if it is a "feature" that has been added.

w220

Dec 2, 2019

I believe the differences are roughtly

1st series: Day and Month ring is not recessed, only the 24 hour indicator and Leap Year is recessed. 2nd series: Day and Month ring are both recessed, and the 24 hour indicator and Leap Year are more deeply recessed. No dividing quadrants on the Leap Year subdial. 3rd series: Similar to 2nd series, but the Leap Year subdial is divided by lines into quadrants.

err_404

Dec 2, 2019

Thank you very much w220! that's exactly what I was looking for. :-)

I have summarized your input in the table below: And to be (almost) complete, I would like to add this special edition with an X leap sub counter, shared by Mike H on the forum :