Patek Philippe Grand Complication 3970E
In today’s frenzied watch market, it’s rare to find a piece from a top-tier brand that still flies under the radar. And yet, the Patek Philippe 3970E may be one of those exceptions. It’s fascinating how one enthusiast might passionately argue for a model’s greatness, while another may overlook its historical weight entirely. Let’s be honest—it’s not easy to convince someone, especially outside the watch world, that a six-figure timepiece is somehow “undervalued.” But that’s exactly what I’m here to do.
Welcome to a deep dive into one of the quiet powerhouses of Patek Philippe’s history: the Perpetual Calendar Chronograph Reference 3970E.
Forget the Nautilus and Aquanaut for a moment. Patek Philippe’s true legacy lies in haute horlogerie—a century-long commitment to the most sophisticated mechanical achievements. Their pioneering efforts include the world’s first perpetual calendar wristwatch, completed as early as 1925. That spirit of innovation culminates in watches like the 3970E, which marries the perpetual calendar with a chronograph—one of the most revered combinations in watchmaking.
This guide will walk you through why the 3970E deserves more love—examining its origins, technical innovations, and the fine details that make it so special.
A Brief History of Perpetual Calendar Chronographs:
The combination of a chronograph with a perpetual calendar is often regarded as the most important combination of complications. But the 3970 didn’t emerge from nowhere—it was the product of decades of incremental mastery.
Though Patek completed the movement for the world’s first perpetual calendar wristwatch before the turn of the 20th century, it wasn’t cased and sold until 1925. In that same decade, Patek also debuted its first wrist chronograph. But these functions remained rare, often reserved for bespoke commissions.
Serial production began with reference 130 (chronograph) and 1526 (perpetual calendar), but it wasn’t until the early 1940s that the two complications were united in one model: the legendary reference 1518. Produced in small numbers, the 1518 cemented Patek’s dominance in complex horology. A steel version famously sold in 2016 for over $11 million, becoming at the time the most expensive wristwatch ever sold.
Its successor, the 2499, launched in the 1950s and is often hailed as the most wearable grail watch from Patek. Produced for over 35 years at a pace of roughly one unit per month, it remains highly coveted. Early 2499s retained the 1518’s square pushers, but later iterations introduced the round pushers we now associate with the 3970E.
Enter the 3970E: A Modern Classic (1986–2004)
The 3970 was introduced in 1986 and produced until 2004, evolving through several series, each with subtle but important distinctions. The first series of the 3970 began to phase out around 1988. By that time, production of the second series was already underway, continuing through to 1990. The third series had already started in 1989—overlapping with the second—and remained in production until 1995. The final series began in the mid-1990s and continued until 2004, though a few exceptions exist beyond that official timeframe. It’s important to view this classification as part of a gradual evolution rather than a set of rigid transitions. There were no strict cut-off points where one series ended and the next began. Instead, components were likely manufactured in batches, and watchmakers used whichever parts were available at the time of assembly. As a result, transitional examples exist, sometimes blending features from different series.
Case:
Starting off with the case. We specifically mentioned 3970E, where the letter stands for the French word “Etanche” which means: waterproof. Yet the first 100 pieces that left the factory had a Snap-on case back and thus are not 3970E but merely 3970. Also the 3971 was introduced, featuring a “exhibition caseback”. From the 2nd series onwards, they fitted the 3970 with a screw-down case back and by doing so they accomplished the production of a waterproof Grand Complication. The 2nd series were usually factory fitted with a solid case back, whilst the 3rd and final series came with both a solid as well as a see-through case back.
To produce the cases, Patek choose their signature metals: precious. White, yellow or pink gold was used alongside Platinum examples. No steel 3970E has ever surfaced nor believed to be ever produced. The case measured 36mm, a tad smaller than both the 2499 as well as the 1518. The lugs are stepped and depending on the country it was delivered to; stamped with different hallmarks. The most noticeable and sought-after is the so-called “Big hallmark”.
The three-piece head itself is quite thick and sports a concave bezel. The side of the case features 4 correctors to set the different calendric features. As mentioned earlier on; the pushers are round and have a traditional placement at the 2 and 4 o’clock position. The crown is ribbed, to improve grip, and is adorned with the Calatrava cross.
Bracelet & Clasp:
The majority was fitted on a leather strap. There are a couple examples that feature a woven bracelet that is integrated to the case, making it not possible to replace it for leather as the lugs were completed removed to offer the most elegant design.
Movement:
The sapphire crystal allowed the appreciator of mechanics to enjoy the beauty of the movement in the 4th, 3rdand optionally but uncommon on the 2nd series. But even if you had a solid case back you’d probably expected the utmost quality for their flagship Grand Complication. Spot-on with the CH27-70Q, a Lemania based caliber. Obviously this Ebauche was modified, for example the addition of the perpetual calendar module, and finished plus decorated to the liking of the Patek artisans. Making it not only reliable but mouthwatering to look at as well. Pay attention to the exquisite chamfering and the Geneva stripes on the surface.
Dial & hands:
Few things are closer to perfection than the dial lay-out of the 3970. Surrounded by an open minute track we can find a lot going on in the center of the dial to display all the different functions, yet it remains a delight for the eye. Above the brand-name one can read the day and month in faceted apertures. The sub-dials at 3 and 9 are also lowered. The last mentioned featuring a chrono-minute counter as well as the leap-year indication. On the opposite part of the dial is the decentral seconds and 24-hour indication. Last but not least: the moon phase and date at the bottom. The text color is contrasting the dial and a lovely classic font is used. The numbers are all Arabic.
Esthetically it’s easiest to differentiate the series by the hands and markers. Both the first and 2nd series come with leaf hands and stick markers. They change to pointy batons and matching hands for the 3rd series and the final execution. Additionally, the font changes over time and so do the day and month disc that graduate from a serif type to a more modern style. There could be overlap in the transition on those between the series. Platinum examples can feature diamond markers instead and only the platinum version is executed either with black or silvered dial.
There are a quite some exceptions to the “regular” dial options, like the one from Eric Clapton that was fitted with a Salmon colored dial and a Breguet number 12. Another possibly unique execution was found with the same dial configuration yet in black, one in platinum and another one in yellow gold. Also sets have been delivered with full Breguet numerals. Equally unusual are the examples with lume. There is a Saatchi Gallery execution in rose gold that was delivered as late as 2011. These are just a few examples but there are many more oddities known. Maybe there are still some undiscovered treasures out there that we do not yet know of!
Conclusion:
In the 2 decades the 3970E was in production, it established itself as the backbone of Patek’s highly complicated lines. A couple years after the turn of the century the production ceased and was followed by the way larger and less elegant 5970. I have had quite a couple of both references and every time I hold them side by side I can’t wrap my head around the fact the 5970 is higher in price. I hope after checking this guide, the watch-community will have a better understanding of the historical importance and sheer beauty of this Patek Philippe with Perpetual Calendar, Moon phase and chronograph function. For some this doesn’t yet qualify for the title “Grand Complication”, even though Patek claims it is, regardless for me this watch is “Grand appreciation”. The 3970E may not scream for attention, but it whispers with authority. And that, perhaps, is the greatest complication of all.