During the throes of the Second World War, Patek Philippe released a watch that would form the basis of its complicated watch production for the remainder of the 20th century and well into the 21st. The Reference 1518, the world’s first serially produced perpetual calendar chronograph wristwatch, was a marvel of mechanical engineering in miniature: Equipped with day, date, month, and moonphase complications, it also featured a dual-register chronograph with 30-minute and running seconds totalizers.
Patek Philippe Perpetual Calendar Chronograph Ref. 1518 - (Image by Christie's)
For the well-to-do client of the 1940s, the Reference 1518 represented the pinnacle of horological accomplishment, providing useful functionality for the traveling businessman. Debuting in 1941, it was replaced in the early 1950s by a watch perhaps even more legendary among diehard collectors, the Reference 2499.
Patek Philippe Perpetual Calendar Chronograph Ref.2499 - (Image by Phillips)
After a remarkably long run, the 2499 was itself succeeded in the mid-1980s by a new perpetual calendar chronograph reference, the 3970. Produced in four series over a period of 18 years, this remarkable reference is — in our humble opinion — one of the most attractive ever made by the maison, with beautiful proportions, a lovely case, and a well-balanced dial that remains legible despite the wealth of information provided by its multiple apertures, totalizers, and hands.
Though its production began in the midst of the Quartz Crisis, Patek Philippe invested heavily in the 3970’s mechanics, using a Lemania 2310 base caliber retrofitted with a perpetual calendar module. Beating at 18,000 vph and providing 60 hours of power reserve, this movement replaced the Valjoux calibres that Patek had previously used in its chronograph wristwatches.
Patek Philippe Calibre 27-70 based on a modified Lemania ébauche - (Image by Collectibility)
In an interesting move that presaged the current pendulum swing away from oversized cases and back to vintage sizing, Patek chose a 36mm diameter for the 3970’s beautifully polished and faceted case with concave bezel — a 1.5mm reduction from diameter of the Reference 2499. (Measuring 13.5mm tall in order to accommodate what Patek referred to as the Calibre CH 27-70 Q, the 3970 wears more substantially than its relatively small 36mm diameter might suggest.) With its stepped lugs, signed crown, dual pump pushers, and discrete corrector at 10 o’clock, this is a case that manages to look both contemporary and timeless simultaneously, exuding an elegance that elevates even the most pedestrian of attire.
Patek Philippe Ref. 3970P dial
The 3970’s dial is a masterclass in horological design: In all configurations, there is a printed 1/5th-seconds track that occupies the outermost layer of real estate. Then, depending upon the configuration and series, the applied indices might be wedge- or baton-shaped, or even diamond-set — each type appears at home within the framework of its complicated surroundings. Beneath 12 o’clock are two perfectly balanced apertures for the day and month. At 3 o’clock, a combination 30-minute totalizer and leap year indicator conserves precious space, while a combination running seconds display and 12-hour totalizer does the same at 9 o’clock. Above 6 o’clock, a handsome, oversized moon phase display is combined with a date indicator.
First-series Patek Philippe Ref. 3970 owned and worn by Tom Brady - (Image by Sotheby's)
The first-series 3970, released in 1986, was a short run of just 100 examples produced in yellow gold and featuring silvered dials, ‘stick’ hour indices, contrasting totalizers, and ‘leaf’ hands. Interestingly, these pieces still featured the snap-on casebacks common to older eras of Patek Philippe’s production — by the time the second series debuted in 1987, it featured a solid, screw-down caseback, giving the watch its “3970E” designation. (“E” for “étanche,” or “waterproof.”) These second-series watches added variety to the proceedings by introducing options in white gold, rose gold, and platinum in addition to yellow gold. Finally, totalizer colors were matched to the main dial colors.
1990s Patek Philippe Ref. 3970E
In 1990, Patek introduced yet another series, shipping each watch with both screw-down solid and sapphire display casebacks. On the dial, ‘leaf’ hands were replaced with ‘baton’ hands, and ‘baton’ hour indices replaced the ‘stick’ variety. Silver-dialed iterations were made more brilliant in color for increased contrast against the totalizers, while the typography used within the day and month apertures transitioned from serif to non-serif on later examples. Finally, in 1995, Patek introduced the fourth and final series of 3970. Functionally identical to the previous series, the fourth series made use of a new serial number range and added a deployant buckle to the included leather watch strap.
Discontinued in 2004 and replaced with the 5970, the 3970 remains a collector favorite, beloved for its wonderfully sized case, ingenious dial layout, and excellent functionality. Combining Patek Philippe’s signature elegance with enough complications to satisfy a well-heeled, world-traveling owner, it’s a distinctly elegant watch in any of its myriad guises. That being said, there’s one particular iteration that we consider “first among equals.”
Patek Philippe Perpetual Calendar Moonphase Chronograph Ref. 3970P
Feast your eyes on this fourth-series Reference 3970P from the early 2000s. Housed in a sparkling platinum case, it features a gorgeous black dial with matching totalizers — nothing terribly out of the ordinary. But look closer, and you’ll discern applied diamond indices — a delightful and subtle use of precious stones, and a far cry from the louder, ‘rainbow’-colored gem-set watches that are currently in vogue.
Delightful to wear, stunning to behold, and timeless in design, this 3970P is simply a magical Patek Philippe that seems as if it coasuld have been made in the mid-20th century; today; or several decades hence. If you’re after a complicated piece with a touch of je ne sais quois, you’d be hard pressed to find a timepiece more compelling.
