This 3970EJ-001 is a fine example of an haute horlogerie complication which has become almost synonymous with : the perpetual calendar chronograph. Highly collectable and coveted, it is considered by many as the pinnacle of Patek Philippe’s watchmaking and design prowess. As a member of this iconic lineage, the 3970 was created in the mid-80s, at a time when perpetual calendar chronographs were scarce. With it, a standard for all modern perpetual calendars was established.

A Historic Lineage 

In 1941, Patek Philippe released the first serially produced perpetual calendar with chronograph, the reference 1518. It was decades ahead of any other brand. It not only marked the beginning of perpetual calendar chronographs for the brand, but of serially produced complicated watches for Patek Philippe, and for the industry in general. The complication has been in Patek Philippe's catalogue ever since. 

More than 40 years on from the release of the original perpetual calendar chronograph, Patek Philippe released the ref. 3970, considered by many to mark Patek Philippe stepping into the modern era. At a time when complicated watches were scarce, this was an important statement of ability from the manufacture. 

A Second Series Example

Following on from the iconic reference 2499, the 3970 was produced from 1986 to 2004, in four successive series. Sold in September 1989, this example belongs to the second series, which is believed to have been made in 650 examples, yellow, rose and white gold, as well as a small handful in platinum. Alongside the first 100 examples from the first series, these are some of the earliest and most desirable iterations of the reference.

Whereas the first series had a snap-on back, the second series marks the introduction of a solid screw-down caseback. This explains why the letter "E" appears in the reference number from this point onwards, referencing the "Étanche", or waterproof, case. Whilst the sub-dials change to match the colour of the dial, the second series also preserves one of the most instantly recognisable features of the first series, the leaf hands, reminiscent of those found on the ref. 1518 or ref. 2499. From around 1990 onwards, the ref. 3970 gradually adopts more contemporary design features, with these earlier pieces embodying a certain vintage appeal. 

Classical design

Classical in design, this 3970EJ features a 36mm yellow gold case, making it 1mm larger than the original 1518 and 1.5mm smaller than its predecessor, the 2499. Evidence suggests that Thierry Stern, CEO of Patek Philippe at the time, felt that this was the perfect size from an aesthetic perspective, and was also likely motivated by a desire to assert the manufacture’s expertise, by producing a complicated perpetual calendar chronograph in a smaller case size.

The dial on this 3970EJ respects the same key design principles as other Patek Philippe perpetual calendar chronographs. It features a classic opalin velouté dial, with yellow gold, pointed baton indexes. You will find the French day and month in apertures at 12 o’clock, the date with moon phase at 6 o’clock, a 30-minute counter for the chronograph and leap year indicator at 3 o’clock, and seconds and day/night indicators at 9 o’clock. This second series features leaf hands, which only appear for around the first four years of production. Overall, the design is balanced and restrained, carrying on the standard for perpetual calendar chronographs set by the manufacture.  

The movement

Powered by the caliber CH 27-70 Q, the 3970 marked Patek Philippe's transition from a Valjoux-based movement to the venerable Lemania 2310 ébauche. Modified and decorated to Patek Philippe's standards and with an added perpetual calendar module, this reliable base movement remained in use for the entire lineage of the 3970. 

Aesthetically, the new caliber is finished to the highest standards. The movement features exquisite chamfering on all angles, polishing and decoration, in the form of Geneva striping. To the wearer's delight, the movement is visble through the sapphire snap-on sapphire crystal caseback.

The Set

This Patek Philippe ref. 3970EJ-001 comes with its original wooden box, Certificate of Origin (confirming sale at Gübelin in September 1989), leather wallet, manuals and additional documents. It comes on one of our grey grained calfskin straps, and is also accompanied by its original Patek Philippe alligator strap and 18K yellow gold buckle.

Closer look