Collecting Patek Philippe’s Perpetual Calendar Chronograph

The story of Patek Philippe starts in 1839 with watchmakers Antoine Norbert de Patek Jean Adrien Philippe forming a partnership that now lives on as Patek Philippe.

Nearly a century later in 1932, Patek Philippe was acquired by the Stern family, who introduced a number of standardizations and technical innovations. First came the simple Calatrava reference 96. Always known for its complicated watchmaking – minute repeaters, calendars and chronographs – Patek then looked to more complex watches.

A perpetual calendar chronograph combines two important complications, or any function on a watch beyond simple time telling. A perpetual calendar – or quantieme perpétuel (QP) in French – keeps track of the date “perpetually,” taking into account the different lengths of the month and leap years with a complex overlay of gears that rival smartwatches in their advanced engineering. (Compare that to an annual calendar, which needs annual adjustment at the end of February because it can’t automatically account for the quirky month’s varying length.) A chronograph is a stopwatch on top of a standard watch.

Both perpetual calendars and chronographs are known for being incredibly complicated mechanical systems, and the combination of these two complications was nearly unheard of in 1941. While Patek and a few others had made one-off perpetual calendar chronographs, they produced nothing at scale.

“Perpetual calendar chronographs, especially those from Patek Philippe, represent the ideal collecting category,” says Jonathon Burford, Senior Vice President and Senior Specialist of Watches at Sotheby’s. “They are highly complex yet easily explainable, and produced in distinct references that can be systematically classified, each with identifiable characteristics.”

It all began with the reference 1518, the first in the lineage of Patek Philippe perpetual calendar chronographs that continues today. Over the years, Patek has made a number of variations on the classic – including versions with repeating minutes, monopushers and split-seconds chronographs – but here we’re focusing on the five main generations of the traditional PCC:

• Ref. 1518 (Produced 1941-54): Patek Philippe’s first serially produced perpetual calendar chronograph. A total of 281 produced using the Caliber 13'''130 Q.
• Ref. 2499 (Produced 1950-85): 349 units produced, using the Caliber 27-70 Q, primarily in yellow gold or pink gold.
• Ref. 3970 (Produced 1986-2004): With a production run of 4,000, this 36mm perpetual calendar chronograph spans the vintage and modern era. Uses a Caliber CH 27-70 Q.
• Ref. 5970 (Produced 2004-10): Utilizing the same CH 27-70 Q caliber, this reference grew in size to 40mm. 2,800 were produced.
• Ref. 5270 (2011-Present): The current model perpetual calendar chronograph employs Patek Philippe’s first in-house caliber, the CH 29-535 PS Q.

Watches

The Complete Guide to Patek Philippe Watch Collecting

Produced as part of Patek Philippe’s Grand Complications, perpetual calendar chronographs have been released under five main reference numbers. Within each, there is often variation, including the use of different case metals and dial colors.

Imagine the turbulence throughout the world in 1941. Amid this backdrop, Patek Philippe introduced the reference 1518, the first serially produced perpetual calendar chronograph. A feat of modern engineering, it distilled the best of Swiss watchmaking into a complicated 35mm wristwatch.

The 1518 has a clean and legible dial that remains recognizable in the modern PCC. At 12-o’clock it contains a calendar aperture displaying the day and month, while the date and moonphase are displayed at 6-o’clock. At 3- and 9-o’clock are the subsidiary chronograph registers.

The dials are usually silver, and all have a tachymeter scale on the outer track – used with the chronograph to track speed over time. The details of the dial are rendered in old-school hard enamel, a process that involves engraving and inlaying the enamel by hand. This technique is designed to be durable over generations, with the hard enamel remaining even when these dials are serviced and cleaned.

The 1518 uses the Caliber 13'''130, an ébauche movement that Patek Philippe modified, decorated and finished to its own exacting standards. This was no small feat – no other manufacturer even attempted a perpetual calendar chronograph caliber until early computer-aided design enabled a new level of micro-engineering.

“It’s hard to overstate the genius of the reference 1518,” Burford says. “Its DNA – both aesthetically and technically – has been a defining thread in Patek Philippe’s history since its introduction in 1941. The perfection of its dial layout has remained virtually untouched over the decades, with only the subtlest refinements in subsequent references. Yet, in my view, none have matched the pure elegance and beauty of this original.”

The Grails: With only 281 examples ever produced and substantially fewer surviving today, any reference 1518 in good condition is considered a grail. Even so, a couple of configurations stand above the rest.

An estimated 58 examples were produced in pink gold, and of these only 15 examples are known to have a matching pink-gold dial. These pink-on-pink examples are some of the most collectible wristwatches across brands, not only for their rarity, but also because of the warm, vintage aesthetic, unmatched by any other watch. The most expensive wristwatch ever auctioned at Sotheby’s was a pink-on-pink reference 1518 from the estate of Prince Mohammed Tewfik A. Toussoun of Egypt, which sold for $9.6 million in 2021.

Even rarer is an example in steel. Just four steel reference 1518 examples are known. In the mid-20th century (or today), a Patek Philippe perpetual calendar chronograph was a luxury product, most typically rendered in gold. Nowadays, this makes any vintage steel Patek, particularly a complicated one, sought after by collectors. 

Collector’s Tip: Beyond rarity, condition is the most important factor determining the collectability of a reference 1518. Examine whether the case maintains crisp, sharp edges; whether the dial is original or shows signs of cleaning and/or restoration; evaluate the functionality of the complicated caliber. A large reason that record-setting pink-on-pink 1518 sold for nearly $10 million was its pristine condition, having sat locked away in a safe for nearly 70 years.

Patek Philippe introduced the reference 2499 perpetual calendar chronograph in 1950, meaning its production overlapped with the reference 1518 by a few years. It remained in production until 1985, evolving over this long production run into four distinct series.

• First Series (1950-60): Features square chronograph pushers, applied Arabic numerals and a tachymeter scale – cues that make it a clear bridge from the reference 1518 to its successor. 
• Second Series (1955-66): Transitions to round chronograph pushers, a beefed-up case and baton indices or numerals while maintaining the tachymeter. 
• Third Series (1960–78): The third series gradually removes the tachymeter scale, presenting a clean and modern design 
• Fourth Series (1978–85): Finally, the biggest evolution of the fourth series is a sapphire crystal, an update to the acrylic (plastic) crystal typically used on vintage watches. 

Like the 1518, most 2499 examples were made in yellow gold, with much fewer produced in pink gold. Two known examples were produced in platinum – one was sold at auction in 1989, and one now sits in the Patek Philippe Museum in Geneva.

Beyond just the metals, this is also when retailer co-signed examples become more common. Signatures from Patek Philippe retailers like Asprey, Tiffany & Co., Gobbi, Howes and others are all sought after by collectors. For example, in 2018, Sotheby’s sold a possible unique Asprey-signed 2499 for CHF 3.9 million – one of the biggest results ever for the reference. Examples signed by Tiffany & Co., the famed New York retailer, also regularly achieve results in the millions. It’s not just the rarity that drives these results – they let the imagination run wild. Close your eyes and you can almost envision a stylish bon vivant strolling into Tiffany & Co. on Fifth Avenue circa 1970, gazing into the fluorescent-lit jewelry cases before finding a magnificent 2499 staring back at them.

The Grails: Besides those two platinum reference 2499 examples (good luck finding those!), pink-gold reference 2499s are particularly collectible, and even better if there’s a little something extra. For example, Sotheby’s sold a pink-gold reference 2499 signed by Gobbi Milano for $7.6 million in 2022. Not only is it the only of its kind, but it’s maintained in excellent condition, important for any collector.

The Sleeper Hits: Many collectors gravitate to the second series 2499 because it’s rarer and it features a larger, updated case with round pushers. That means later generations can often go undervalued. The third series had a much longer production run, but is still difficult to find in pink gold. While still prioritizing originality and condition, look for nuances like this to find value in the later-series reference 2499 examples.

Collector’s Tip: Many collectors view the reference 2499 as the ultimate Patek Philippe. It has a larger 37.5mm case (compared to the 1518 or later reference 3970) made by respected casemakers Vichet (first series) and Wenger (later series). Beyond its rarity, it strikes a balance between vintage charm and contemporary appeal.

References 1518 and 2499 represent the very top of vintage watch collecting. Collectors aspire to own any example, and seven-figure auction results can make your eyes glaze over. The successor, reference 3970 perpetual calendar chronograph, represents Patek’s transition into the modern era. Introduced in 1986 and remaining in production until 2004, it is also much more common. Estimates put production at about 4,000 pieces over a two-decade run.

This makes the 3970 the most accessible of Patek’s perpetual calendar chronographs, although this has begun to change in the past few years. Along with its sister reference 3940 perpetual calendar (sans chronograph), these complicated watches represented a return to traditional, mechanical watchmaking after the quartz revolution of the 1970s. Especially in the wake of Patek’s 150th anniversary in 1989, references 3970 and 3940 became the core of Patek Philippe’s rebirth as a revered manufacturer of Swiss watches.

Like the 2499, the reference 3970 is now broken down into four series by collectors:

• First Series (1986-88): Only 100 examples produced, all in yellow gold. These use snap-on casebacks and typically feature a vertically brushed, two-tone dial.
• Second Series (1987-90): Introduces a water-resistant screw-down caseback, but keeps the same applied square markers and feuille hands as the first series. Produced in yellow, white and rose gold, as well as platinum. 
•  Third Series (1989-95): Transition to faceted hour markers, baton hands and a brighter dial. Patek also began delivering a sapphire and solid caseback for all examples.
• Fourth Series (1994-04): Similar to the third series, but Patek moved from a pin buckle on the strap to a modern deployant clasp. The fourth series is best distinguished by case and movement number batches. 

The Grails: In the last few years, the first series reference 3970 has become particularly sought after by collectors. Only 100 examples were made, and it’s thought many have been damaged because its distinguishing snap-on caseback provides little water resistance. In December 2024, Sotheby’s sold a first series 3970 for $312,000, previously in NFL quarterback Tom Brady’s collection. Even better, this was the second 3970 example ever produced; over the coming years, this promises to be an exceptionally collectible watch.

The Sleeper Hits: In recent years, collectors have caught on to the rarity and importance of early first and second series 3970 examples. First series prices have climbed to nearly match late-series 2499 prices. For those looking for value (as much as such a term can be used with a straight face for a six-figure watch), look for a third series 3970 with its full set – original box, papers and all the fixings. While not as rare as early 3970 examples, finding a full set in collectible condition is increasingly difficult.

Collector’s Tip: Alongside the 3970, Patek also produced the reference 3971 through the late 1980s. It’s the exact same as the 3970, but features a sapphire caseback. Like the 3970, the first series 3971 has a snap-on caseback, with later examples moving to a screw-down caseback. By the third series 3970, every watch was delivered with both a solid a sapphire caseback, allowing Patek to discontinue the separate reference 3971.

Getting Technical: The reference 3970 uses the Patek Caliber 27-70Q. Based on the Lemania 2310/2320, it was heavily modified and finished in-house, becoming the first chronograph to carry the Geneva Seal. Designed by Albert-Gustave Piguet in 1942, this movement famously served as the base for Omega’s Caliber 321, which was flight-certified by NASA, while its compact 27mm size allowed for the 3970’s svelte proportions.

In 2004, Patek introduced the reference 5970 perpetual calendar chronograph. Its biggest difference compared to the 5970 is the diameter. Up-sized to a modern 40mm, it offered a welcome update to modern collectors who favor larger watches. Inside, the 5970 uses the same Patek Caliber CH 27-70 Q as the 3970 – the last time Patek Philippe would use a Lemania-based movement in its perpetual calendar chronograph lineup.

Produced until 2010, the 5970 had a relatively short production run. Estimates put production at 2,800 units: lower than the 3970, but produced across a much shorter timeframe.

The 5970 is a fully modern watch, produced in the four traditional metals, each given slightly different reference numbers:

• 5970G (2004–07): The first of the two introductory options for the 5970 features a white-gold case and silver dial, giving it a monochromatic, modern look.  
• 5970R (2004–09): Introduced alongside the white gold, it features a pink-gold case and silver opaline dial. The pink-gold 5970 is generally thought to have been the most popular, with more than 1,000 produced. 
• 5970J (2008): The rarest variant, with a warm, yellow-gold case and a silver opaline dial, produced for just one year.
• 5970P (2009–10): The most luxurious, with a platinum case and striking black dial, produced towards the end of the 5970’s production and generally regarded as the most collectible.

The 5970’s case and dial proportions are generally regarded as the perfect balance between classic and modern – less diminutive than the previous 3970, but more wearable than the successor 5270. Even as someone with small wrists, I recall being struck by the 5970’s wearability the first time I tried one on. It’s got presence, but the down-turned lugs hug the wrist to make for a manageable profile.

The Grails: During the 5970’s production run, Patek Philippe would still produce special commissions for important clients. Every so often, a beautiful, unique example with a special dial configuration or color will appear. Often, these have vintage-inspired cues like Breguet numerals or warm dial colors that make collectors drool. In 2022, Sotheby’s sold one of these commissions in white gold with a gorgeous salmon dial for $1.3 million – a combination that could melt even the most hardened of hearts.

Collector’s Tip: Out of production for just over a decade, the 5970 perpetual calendar is still coming into its own as a collectible wristwatch. When the 5970 was introduced in 2004, it had an MSRP of $89,600 – and New York Magazine wondered if that might be crazy. Twenty years on, auction prices have steadily crept up. Unlike hype watches, the 5970 never experienced a bubble. These are complicated watches that take time to understand, and because of that, the market has been – and will continue to be – a slow burn.

The Patek Philippe reference 5270, introduced in 2011, replaced the 5970 as the brand's flagship perpetual calendar chronograph and is still in production today. Its biggest update is on the inside, as it features Patek’s first in-house chronograph movement, the Caliber 29-535 PS. Patek didn’t hold back for its first manufacture caliber, leveraging an impressive six patents to refine the accuracy and usability of the mechanism.

The 5270 retains the elegance of the perpetual calendar chronograph lineage, but with plenty of aesthetic updates. My favorite design flourish is the swooping, stepped lugs – they’re faithful to the references that came before it but wholly unique.

Since 2011, Patek has produced the 5270 in the full range of case metals and with a variety of dial colors:

• 5270G (2011–15): Originally introduced with a silver dial to lukewarm reception, Patek eventually added a blue dial to the white-gold reference 5270G. 
• 5270R (2015–Present): The rose-gold version of the 5270 has a warm, classic appeal with a cream-colored dial and rose-gold markers. In 2018, Patek updated the 5270R with a black dial and luscious, matching rose-gold bracelet.  
• 5270J (2020–Present): The yellow-gold version stands out with its vibrant color, combining a bold aesthetic with a sophisticated silver opaline dial that feels both timeless and contemporary.
• 5270P (2015–Present): As with previous perpetual calendar chronographs, the platinum 5270P is the premium offering. First offered with a rich black dial and later updated to a lacquered green dial for a more modern look. 

As of 2025, the reference 5270 perpetual calendar remains in production, which means its story is still being written. Examples can even sell at auction for less than its retail price. But if history is any indication, it’s only a matter of time until collectors appreciate the 5270.

Collector’s Tip: If you want to stir up a niche debate among Patek collectors, ask them their opinion on the 5970’s chin. Look at the 6-o’clock subdial on early 5270 examples, such as the blue 5270G above, and you’ll it has a small extension, designed to accommodate the tachymeter scale. The chin prominently features towards the beginning of the 5270’s production, but Patek would phase it out in later versions.