The Complete History of the Audemars Piguet Perpetual Calendar

The following article is written by Wei ‘Le Wei’ Koh, in collaboration with Michael ‘Le Mic’ Friedman and Pygmalion Gallery, with thanks to Tom Chng

Wild, Iconoclastic, Rebellious

Imagine for a moment you are invited to a dinner at a stately ancestral home. And there seated before you are the living, breathing personifications of the Holy Trinity of high Swiss watchmaking brands in dinner-suited human form. The first to greet you is Patek Philippe who in this family is the golden child. He’s the Anderson & Sheppard-tailored Fulbright scholar, matriculated from Harvard Law School and Trinity College, Cambridge, whose future is guided by divine inexorable perfection.

The second named Vacheron Constantin is darker, tall, lean and immaculate in Caraceni; introspective but fiercely brilliant, holding forth on the synergistic link between Euclidean geometry and Sufi mysticism.

Then you hear the door slam. There with the paint-splattered trousers of his Cifonelli tuxedo stuffed into motorcycle boots, his shoulder-length hair in disarray from racing helmetless on his vintage Norton from the bucolic brookside cottage where he was initiating his mother’s freshly divorced friend into the art of Tantra, is the wild child.

He has hypnotic, movie-star looks. Think Jason Momoa channeling Byron. This is Audemars Piguet. Because while Audemars Piguet’s brand of Swiss high watchmaking is unassailable in its finish and elegance, the quality that I love most about the Le Brassus-based manufacture is its wild, iconoclastic, rebellious creativity which has yielded some of the greatest game-changing moments in horological history and shaped the entire concept of style combined with technical innovation in the 20th century and beyond.

The Quartz Crisis (1970s into 1980s)

Five amazing individuals — Audemars Piguet’s then CEO Georges Golay, Jacqueline Dimier, Michel Rochat, Jean-Daniel Golay and Wilfred Berney — were behind the audacious perpetual calendar project that saved AP during the Quartz Crisis

Many of Audemars Piguet or AP’s most stalwart devotees credit the extraordinarily audacious Gérald Genta-conceived Royal Oak as rescuing the brand from the onslaught of the Quartz Crisis that laid low so many of its competitors. And without doubt the Royal Oak was a seismic act of watchmaking brilliance.

But in fact the true heroes of Audemars Piguet, the men that came up with a brilliant tactical plan to combat the ravages of the cheap quartz invasion, had names that sounded like resistance-fighter aliases. They were Michel “Le Mic” Rochat, Jean-Daniel Golay and Wilfred Berney. For the purpose of this story, they shall forthwith be referred to as Team RGB.

And they would be aided by two extraordinary individuals: the first, Georges Golay, the boss of AP (known as “Uncle George” to the Bottinelli family, one of the families behind the brand) and a true brilliant leader during this seminal period; and the second, a design genius named Jacqueline Dimier, who was in some ways the protégé of the legendary Gérald Genta.

How did they stave off the destruction of the Quartz Crisis that had other brands abandoning mechanical watchmaking, destroying their lathes and presses and selling off movements by weight? With the creation of the world’s thinnest automatic perpetual calendar, a movement that to this day resonates as one of the most significant acts in horological history.

Says Michael Friedman, AP’s beloved historian and head of complications, “Think about it in the context of 1978. No one was making complicated watches, let alone perpetual calendars. In fact the only other brand that has made a serially produced perpetual calendar wristwatch up until this point was Patek Philippe.

Their watch at the time is the reference 3448 (launched in 1961), a round ‘disco volante’ shaped watch that is 37mm in diameter and 11mm in thickness. Then we unveiled the reference 5548, that is so significantly thinner at 7mm.

It is such an audacious watch. Because it was saying to the world that’s being swept up by the quartz craze, ‘Hang on, look what we are capable of with mechanical watchmaking.’ In the size of a quartz watch, we’ve placed a mechanical supercomputer. And because of the lean elegant dimensions of the 5548, it becomes a symbol of modernity like the Royal Oak before it.”

What is important to understand in the context of the era is that while quartz watches had begun to dominate consumers with their unfailing accuracy and cheap price, there were no complicated quartz watches. Complications and in particular the perpetual calendar was the expressed realm of mechanical watchmaking. (A lesson not lost on a young Jean-Claude Biver who was working at Audemars Piguet at the time and would subsequently set up Blancpain specifically to champion complicated mechanical watchmaking). But of course, if we could time travel, the question to ask the trio of Rochat, Golay and Berney would be, “why the perpetual calendar?”

OK, let’s pause here to explain what a perpetual calendar is. The reason we have the four-year leap-year cycle is that the 365-day year is actually shorter than the true solar year (365.25 days approximately). Which means each year we build up a small debt, which is accommodated for every four years with an additional day that is February 29th.

If you want to get even more technical, every 100 years, the leap year is omitted because the leap day creates a slight time overage. Anyway, a perpetual calendar is an extraordinary watch that displays the full calendar information of day, date, month, usually phase of the moon. Now perpetual calendars are smart. Like Asian mothers, they are always right. If they were dogs, they would be MENSA-qualified border collies capable of solving complex algorithms, while composing haiku poetry, singing Verdi’s operas in pitch-perfect phonetically flawless Italian while herding sheep. Why?

Because they are capable of automatically compensating for the shifting 30/31 rhythm of the months as well as accounting for the 28 days in February, and even knowing when the extra day every leap year is.

The perpetual calendar, an incredible mechanism that tells calendar information in perpetuity and compensates for leap years, was invented by Thomas Mudge.

The first watch with a perpetual calendar mechanism was created in 1762 by British watchmaker Thomas Mudge and became a popular feature of pocket watches for discerning gentlemen the following century. The first serially produced perpetual calendar wristwatches were the 1518 and the 1526 both launched by Patek Philippe in 1941.

It should be noted that for the better part of the 20th century, it was only Patek Philippe and Audemars Piguet that produced perpetual calendar wristwatches in series. Wearing a perpetual calendar wristwatch in the context of the time was like showing up to a dinner party with a cray supercomputer strapped to your wrist but expressed with extraordinary elegance and beauty.

OK, back to the heroic triumvirate of “Le Mic” Rochat, Golay and Berney or Team RGB. Why did they decide to create an ultra-thin automatic perpetual calendar movement? Well, as it turns out, Audemars Piguet has had one of the deepest and most meaningful histories with this complication. Indeed, we can go all the way back to Jules Louis Audemars, one of the maison’s two founding fathers.

Before creating the brand along with Edward Auguste Piguet in 1875, Audemars first had to graduate from watchmaking school. In order for this to happen, he had to create a “school watch,” a representation of his mastery of the education imparted to him.

Audemars, clearly a horological baller from the start, presented an incredible quarter-repeating pocket watch, with dead seconds (where the second leaps forward only at each second rather than moving incrementally) and with — yes, you guessed it — a perpetual calendar.

Look at this watch and you’ll notice that the full leap-year cycle is displayed within the subdial at 12 o’clock, which means a full 48 months with a delineation of which year in the cycle (shown as 1st, 2nd, 3rd or 4th) each month falls.

This was the traditional way in which the leap year was shown. It should be noted that the leap-year display was also frequently omitted from pocket watches. Take a look at the Patek Philippe pocket watch made for American automobile manufacturer James Ward, for example, where in order for the watch to be set, it had to be sent to a watchmaker who would usually take the dial off to do this.

The fact that Audemars decided to display the full cycle would set an important precedent for an amazing wristwatch that would be unveiled a full 80 years later by the brand that would bear his name.

Reference 5516
The First Perpetual Calendar Wristwatch with Leap-Year Display

According to Michael Friedman, when the onset of the wristwatch era went mainstream in the 20th century, Audemars Piguet would occasionally dip its feet into calendar complications. However, these were invariably unique commissions for discerning and wealthy patrons. The total number of wristwatches with calendar complications that were made before 1950 is believed to number 208 and includes this extremely handsome two-tone reference 5503 complete calendar which is, from a design perspective, a clear kindred spirit to the reference 5513 which inspired this year [Re]Master 01 Chronograph.

But then in 1955, Audemars Piguet brought the real horological heat with the reference 5516, the world’s first perpetual calendar wristwatch with leap-year display.

The Pre-Series Ref. 5516

In total there were 12 examples of the reference 5516 made. Three of these watches were made with perpetual calendars but without leap-year indicators. Michael Friedman refers to these watches as “pre-series” watches and we have a nice image of two of them here.

This black and white image from page 128 of the book Audemars Piguet 20th Century Complicated Wristwatches shows two of these watches. Watch number one, which bears the serial number 52722, was created by a watchmaker who found a perpetual calendar mechanism that he referred to as under-dial works that had been “hanging around for 60 or 70 years,” and decided to mate it to a caliber 13VZSS to produce a rather magnificent wristwatch.

The work was done in 1947 and the watch was eventually sold in Bangkok in 1951. The second watch bears the movement number 52542 and was made in 1948 and delivered to famous retailer Gübelin in 1950. Notice that it is characterized by a much more stylized and expressive case. And that in this case, the dial features date that is displayed by a central hand read off a scale printed at the perimeter. What is interesting is that the third of this pre-series exists. It is similar to this watch and was sold to Patek Philippe in 1961.

The First-Series Ref. 5516

The true expression of the legendary 5516 was unveiled in 1955 with the watch pictured here. In total three of these watches were made. What makes them incredibly distinct is the use of the full 48-month leap-year display similar to the display created by Jules Audemars for his school watch in 1875. Information here is beautifully and artfully arrayed. Says Friedman, “What is incredible is the level of skill used to create these enamel dials. Look how tiny and fine the detail has to be to accomplish this 48-month indication.”

Date is told off the central hand relative to a scale printed at the perimeter of the dial, similar to the two pre-series 5516s made in 1948. Phases of the moon is shown at 12 o’clock, while the month is actually shown twice, one in a clean, easy-to-read indicator at three o’clock and a second time within the dense information-packed 48-month leap-year cycle at six o’clock. Based on the abundance of information on the dial, it is understandable that date, which is the most vital information after time, is displaced to the dial’s perimeter for maximum legibility. Finally, at nine o’clock you see the days of the week. Hour and minute is told off central gold hands while the seconds are displayed on a small gold hand coaxially mounted to the blued hand that tells the leap year.

All blued hands are related to calendar information and all gold hands are related to time. It is hard to overstate the revelation that the 5516 represented. For the first time, someone could set their perpetual calendar themselves, rather than have to bring it to a watchmaker to remove the dial and set it. Interestingly, the watch pictured here was made in 1955 and sold to Vacheron Constantin in 1959.

OK, let’s look at the 5516 in comparison to the only other serially produced perpetual calendar around at the time, the Patek Philippe 2497. The Patek can be viewed as minimalist, even reductionist, while the Audemars is just the opposite, redolent with information. The AP is bold in styling while the Patek is restrained. Let’s say the Audemars is the barefoot Brigitte Bardot, all suntanned and undulating hips in Vadim’s And God Created Woman to the Patek’s graceful, elegant Grace Kelly. If these watches were women, there’s one you might want to take home to your parents and another one you might want to make ravishing love to. I’ll leave you to decide which is which.

The Second-Series Ref. 5516

The final six examples of the Audemars Piguet reference 5516 are a great leap forward in design language. All six of these watches were put into production in 1957 and sold between 1963 and1969.

The major difference between these watches and their predecessors is that at this point, Audemars Piguet decided to eschew the busy 48-month display of the leap-year cycle and replace it with a clean display at 12 o’clock that minimalistically but perfectly expresses where in the cycle you are at.

Could it be that Philippe Stern would notice this display when he created the 3970 and 3940, both from 1985, which are the two first Patek Philippe perpetual calendars that also use this form of display for the leap year? (The first Patek with leap-year indicator would be the 3450 from 1981, which would display it in an aperture).

As a result of this key change, the dials of these second series 5516 watches are significantly cleaner. It is, however, interesting that of these six watches, one watch number 73012 would retain the full 48-month display and place it within a tiny subdial at 12 o’clock, leading me to believe reading it could only be accomplished using a magnifying glass.

The Watch That Saved AP
The Ultra-Thin Automatic Perpetual Calendar Ref. 5548

The year is 1969. Seiko launches the Astron, a seemingly innocuous, accessibly priced digital quartz watch oscillating at 32,768Hz and capable of far greater accuracy than any high frequency observatory-certified mechanical chronometer, that unleashes the Quartz Crisis. (It should be noted that the Swiss were also working on quartz technology but were beaten to market by Seiko).

As a result of the massive upheaval, innumerable venerable watchmaking houses face insolvency and extinction as orders for their mechanical watches dry up overnight. For the Swiss watchmaking brands, it became a question of survival.

It’s well known that in 1972, just as the onslaught was hitting Switzerland, Audemars Piguet unveiled what should objectively be recognized as the single most audacious watch in the late 20th century, the legendary, iconic Royal Oak. It was a watch that from a design perspective obliterated any link with the past.

Instead, it utilized its unconventional case construction with exposed screws running through the octagonal bezel to the back case, replete with exposed rubber gasket, as its very own design leitmotif. It was also the world’s first integrated bracelet sports chic watch, where the Gay Frères-manufactured bracelet was conceived as one seamless part of the organic totality of the watch. Interestingly, even though the watch was a massive 39mm in diameter, which resulted in the nickname “Jumbo,” it was actually remarkably slim at 7.2mm thanks to the use of the Jaeger-LeCoultre-designed caliber 2121 that was only 3.05mm in thickness (This is caliber 2120 but with a date wheel).

It was steel but audaciously priced like a gold watch; in fact, for its 3,650 Swiss-franc asking price, you could actually buy a Jaguar. Amazingly, and as an irrefutable demonstration of AP CEO Georges Golay’s foresight and testicular fortitude, the brand ordered 1,000 steel cases for the reference 5402 “A” series of the Royal Oak. A second 1,000 cases would be ordered subsequently so that the total number of A-series 5402 watches is 2,000 examples.

Eventually, the Royal Oak became the unofficial membership badge of a group of international elite that could afford to drop the equivalent of a car on a steel watch.

However, what is important to understand is that it took time for the Royal Oak to catch on. Indeed, it was only its adoption by a certain social elite including Italian playboys such as Gianni Agnelli, members of royalty such as King Juan Carlos of Spain and Prince Michael of Kent, and designers like Karl Lagerfeld, that the watch gained traction and became almost a club emblem of the international set. Setting an amusing precedent to Richard Mille, its staggering asking price became one of the attractions of the Royal Oak because it quietly but pointedly expressed that you could drop the equivalent of a well-appointed automobile on a steel wristwatch.

Says Michael Friedman, “All this is true. But to say the Royal Oak rescued Audemars Piguet from the Quartz Crisis is not completely accurate. The Royal Oak took some time to catch on. I like to consider it the first step, the overture to our recovery during this challenging time. To me, the watch that really reversed our fortune was the reference 5548 Ultra-Thin Perpetual Calendar Automatic watch launched in 1978, at the very height of the crisis.”

By 1978, the number of watchmakers in Switzerland had dropped from 1,600 to 600. For Audemars Piguet and the trio of watchmakers behind the 5548 perpetual calendar project, their motivation was not just to create a game-changing complicated wristwatch, but to keep watchmakers employed. Incredibly, the project to create the world’s thinnest automatic perpetual calendar was not the result of a management meeting but a project started in secrecy. Almost like resistance fighters, Team RGB would work on this project during their off hours, and meet surreptitiously in the dark of night.

The unit’s leader was Michel “Le Mic” Rochat, a 34-year veteran of Audemars Piguet, which means he would have been with the manufacture during the creation of the reference 5516. He tapped Jean-Daniel Golay, the man who founded the technical department, and together they began constructing their plans for this movement using cardboard mock-ups. They then went to the Vallée de Joux watchmaking school for help drawing up their blueprints. Finally, they approached Wilfred Berney, the founder of the after-sales service department, to discuss practical implementation.

It was Berney’s idea that the ultra-thin calendar module should be mated to the caliber 2120 which drove the Royal Oak. This proved to be the perfect base caliber for their project. The 2120 is a thin movement that is a mere 2.45mm in thickness. But it is very robust thanks to its free-sprung Gyromax balance wheel, and also supplied a constant source of optimal energy necessary to drive the calendar mechanisms without affecting amplitude, thanks to its ultra-efficient winding system.

In this movement, the rotor has all its mass placed to the periphery. In fact, if you look at the underside of the rotor, you will see that it actually steps down into the movement. The rotor is supported around the full perimeter of the movement by a circular rail and runs on ruby rollers for added smoothness and efficiency. It also features a “suspended” mainspring barrel, meaning there is no bridge for this element, decreasing thickness of the movement. It’s good to know all this because it will come back to bear when Audemars Piguet will unveil the ultra-thin perpetual calendar caliber 5133 in 2018’s Royal Oak RD#2.

Incredibly, the entire thickness of the 2120/2800 perpetual calendar caliber measured only 3.95mm with a movement diameter of 28mm. The module would be made for Audemars Piguet by complications specialists Dubois Dépraz. Says Michael Friedman, “This is the way watchmaking worked at the time with maisons collaborating with many specialists’ business in the Vallée de Joux. AP had a long-standing and excellent relationship with Dubois Dépraz so it was natural to work with them in this project.”

In 1977, the trio surprised Georges Golay with this incredible movement. He was simply blown away. Says Oliviero Bottinelli, my friend from the afore mentioned Bottinelli family, “Uncle George was a true visionary. He took chances when the stakes were highest because he understood that the key to our survival during the Quartz Crisis was audacity and creativity. To make what no one else could dream or dare to create.”

Such was Golay’s confidence in the project that despite the inclemency of the times, he immediately commissioned 159 watches, which was almost as many as the total number of calendar watches made since 1924 by AP. But a great movement would be nothing without a great design and Golay immediately set an exceptional woman named Jacqueline Dimier to work.

The brilliant Jacqueline Dimier had joined AP in 1975 and was responsible for the design of the first ladies Royal Oak in 1976 amongst many other projects. She would later go on to design the world’s first wristwatch tourbillon produced in series, which would be launched in 1986 and which would feature the famous sunray guilloché inspired by the Egyptian sun god, Ra.

For the 5548, it must be clear that Dimier was aware of the watch that was her sole competition — the only other automatic perpetual calendar being made in series, the Patek Philippe 3448 launched in 1961. She would have also taken note that the Patek 3448 was 37mm in diameter but a full 11mm in thickness. The 5548 would be 36mm in diameter (up to 37.5mm in some executions) but measure only 7mm in thickness, which was a huge difference from the 3448.

The design of the 5548 is best described as Zen reductionist elegance. While the 5516 was all about exuberant information overload, the 5548 pared everything back to its core essential. Of course the first thing you’ll notice is there is no leap-year indicator as it was perceived to be somewhat superfluous on such a cool minimalist watch. The indication would only return in 1995. The dial is incredibly legible with the months at 12, the date at three, the moonphase at six and the day at nine o’clock.

Note that while the 5516 was distinguished by its massive central date (something that would be revived in 2015 with the caliber 5134’s weeks display) here the date is calmly displayed within the confines of the subdial at three o’clock. Everything is lean and restrained, markers are baton as are the bands with just printed indexes at 12, 3 and 9 offering contrast. The lugs taper dramatically to a very fine point; indeed the only dramatic element is the sharply double stepped bezel.

The overall effect is a watch that feels significantly more modern than the Patek 3448. Part of this was that the Patek was created in the bucolic era previous to the Quartz Crisis, while the 5548 was unveiled in the midst of the quartz maelstrom. It is clear that Dimier and the trio of Rochat, Golay and Berney wanted their watch to be a statement of what mechanical watchmaking was capable of. Here in a case the size of its quartz competition was a mechanical masterpiece that would never age, become obsolete or require a battery change, capable of telling all calendar information in perpetuity.

Upon its launch, the 5548 was a smash success. Over 7,219 caliber 2120/2800 movements would be manufactured over the caliber’s life span. A total of 2,183 documented examples of the 5548 were made during the watch’s amazing production run between 1977 and 1991. Of the watches made, yellow gold was the most popular with 2,066 examples made. There were just 80 white-gold watches made, 32 in platinum, four in steel and just one in rose gold. Incredibly, in 1984 the model reached its peak in popularity with an amazing 675 examples fabricated. When launched, the price of the 5548 was 15,500 CHF (compared to a Royal Oak 5402, which was priced at 3,950 CHF at launch).

Says Michael Friedman, “As you can see it was really the 5548 that rescued Audemars Piguet. What I love about this was, at a time when no one was creating complicated watches, let alone an all-new, record-setting ultra-thin automatic perpetual calendar, that’s precisely what AP did and it made all the difference. Can you imagine we made 675 of these in 1984? That year there were only 1,066 perpetual calendars in Switzerland.”

Another important thing to note is that in my opinion the Audemars Piguet 5548s are massively undervalued considering their technical innovation and historical significance. I’ve seen yellow-gold examples selling for just over 10,000 US dollars which to me is incredible. I would wholeheartedly recommend collectors and in particular those looking to find an accessibly priced, beautifully designed, culturally significant and groundbreaking perpetual calendar to look at these with a focus on the rarer metals. Note that earlier watches have a “Swiss” signature at six o’clock, while watches from 1982 onwards have a “Swiss made” stamped instead. The 5548 can be distinguished from the very similar 25657 in that their subdials are level with the rest of the dial. In the 25657, the subdials are sunken.

…the Audemars Piguet 5548s are massively undervalued considering their technical innovation and historical significance.

If you want to know more about the 5548, please check out this excellent article by Ben Dunn.

The reference 25657 (around 1984, AP started slapping a “2” in front of all their references so the 5548 became the 25548) was introduced around 1982. It was made in a total of 1,821 pieces. 1,309 in yellow gold, 362 in pink gold, 128 in platinum, 16 examples in white gold, five examples in two tone and one example in steel. It is almost identical to the 5548 but distinguished by its sunken subdials. The 25657 was also a canvas for some wonderfully expressive dials, in particularly the stunning engine-turned models.

It was also executed in other interesting dials including an Arabic index model, a Tuscan-dial model with an unusual decorative pattern and a wild version with a four-leaf-clover-shaped sapphire and dial. To me, the Tuscan dial is one of the all-time most beautiful watches of this era and our friend Tom Chng, the man behind the Singapore Watch Club, happens to be a proud owner of this model.

The reference 25661 is the same watch as the 25657, but with a display back offering a view of the magnificently decorated movement. It was made in 342 examples, with 244 in yellow gold, 37 in platinum 32 in white gold and 29 in pink gold. On the dial side of the 25661, note the use of the applied dot markers at 12, 3 and 9.

Here is an image of a beautiful salmon-dialed 25661 model sold by Silas Walton of website A Collected Man.

What are the most beautiful of the early round-cased Audemars Piguet perpetual calendar watches? To me, they would have to be skeletonized or openworked models made from 1988 to 1993 under reference 25668. These were made in 205 examples. 94 in yellow gold, 79 in platinum, 30 in pink gold and two in white gold.

Some Excellent Examples of Perpetual Calendar Wristwatches Birthed from the 5548 Family

An Icon is Born
The Royal Oak Perpetual Calendar

In 1949, British author George Orwell imagined 1984 to be a dystopian future, where the UK, now known as Airstrip One, was ruled by a draconian, authoritarian government (some have drawn amusing parallels to Singapore) led by a personality known as Big Brother. But the reality was markedly different. Ronald Reagan was in the White House and the global economy was booming. The yuppie had become a cultural phenomenon and an entire generation was focused on upward mobility.

In the theaters that year were optimistic, escapist fantasy-driven fare like Daryl Hannah’s debut vehicle, Splash, Ghostbusters, Indiana Jones and the Temple of Doom, and the seminal directorial debut of James Cameron, Terminator. This film would introduce us to a seven-time Mr. Olympia bodybuilder-turned-actor and future Audemars Piguet ambassador named Arnold Schwarzenegger. And while AP was certainly not out of the precarious shoals of the Quartz Crisis, the company was stable.

The creation of the 2120/2800 caliber had allowed the manufacture to double its watchmaking team, creating precious jobs in the watchmaking hotbed of Le Brassus in Switzerland’s Vallée de Joux. In 1984, Audemars manufactured an incredible 675 watches with this movement, comprising more than half of all the perpetual calendars made in Switzerland that year. At the same time the Royal Oak had become a phenomenon, a symbol of style and modernity and the membership badge to a very elite group.

It was therefore not a stretch of the imagination that Golay would tap Dimier to marry the two iconic creations of Audemars Piguet during the ’70s, in what has to be considered one of the most important watches of all time. The Royal Oak Perpetual Calendar was born in 1984, and became an instant icon. It represented the union of the two most revolutionary watchmaking acts of Audemars Piguet — the iconoclastic Royal Oak and the world’s thinnest automatic perpetual calendar movement, the 2120/2800.

The 5554 would introduce one of Audemars Piguet’s most successful models, a watch that is still as relevant today as the year it was created. For the purpose of clarity, I’ve divided the eras of the Royal Oak Perpetual Calendar watches into three categories. The first are the non-leap-year indicator watches made from 1984 to 1993. The second category pertains to the leap-year indicator watches from 1995 to 2014. Note that throughout this time, the watch remains largely unchanged. It measures 39mm in diameter and is 9.3mm in thickness which is just 2.1mm thicker than the 5402’s 7.2mm case. And then from 2015 to the present day, when the case of the watch is enlarged from 39mm to 41mm and receives a slightly thicker movement with annular week display (an increase from 3.95 to 4.31mm) that results in a case that is just marginally thicker at 9.5mm.

Think about it from the perspective of the time. There was basically no other shaped, integrated sports chic perpetual calendar around. The Patek 3448 was about to transition to the 3940 the following year. But it was a round classic watch. Blancpain was still focused on its caliber 6395 and years away from launching their perpetual, and their watch was still thicker than both the 5548 and the new Royal Oak Perpetual Calendar Automatic. The Royal Oak Perpetual Calendar was something the world had never seen before — a total departure from the past, a modern case and a modern movement united to create one of the most groundbreaking complicated timepieces of all time.

The Royal Oak Perpetual Calendar was something the world had never seen before — a total departure from the past, a modern case and a modern movement united to create one of the most groundbreaking complicated timepieces of all time.

Part I
The Non-Leap-Year-Indicator Watches, 1984 – circa 1993

1,630 watches. References 5554 (25554), 25636, 25654, 25624 and 25651

Before I get into the history of the Royal Oak perpetual calendar I’d like to shout out this article by watch collecting lifestyle.

OK, the 5402ST Royal Oak A series measured a scant 7.2mm in thickness with a movement that was 3.05mm. In comparison, the Royal Oak Perpetual Calendar 5554 measured 9.3mm in thickness with a movement that was 3.95mm in thickness.

With the Royal Oak, part of its attraction is the dynamic tension between its muscular presence on the wrist and its svelte aquiline thinness, and so when approaching the 5554, the brand would be careful to retain this appealing contrast. While the case diameter stayed at 39mm, AP managed to place all the perpetual calendar information into the watch while increasing the thickness to only 9.3mm, which was still significantly thinner than a Patek 3448 which measured 11mm.

The First-Generation Ref. 5554

The 5554 is the grail of these watches based purely on its historical significance. And accordingly, these first-generation watches are relatively rare. Initial launch series comprises just 279 examples, with 229 examples in yellow gold, 49 in steel and just one watch in platinum. Says Michael Friedman, “These early watches had smooth dials without the hobnail decoration that you see in later models or associated with the 5402. So if you find a reference 5554 and it has a different dial, it is likely that it has been swapped or changed during a service.”

Just to keep things exciting, apparently in 1985, the manufacture released one single reference 25624 Royal Oak Perpetual Calendar in yellow gold but set with diamonds along the edge of the bezel. The last known whereabouts of this watch relates to its sale on the collectors’ marketplace at WatchProSite.com, dating back to 2017.

The Second-Series Ref. 25636 with Skeleton Dial

In 1986, the ref. 25636 with a beautiful skeleton dial was launched. When I say “beautiful,” I mean “sell your children and your kidney to fund the purchase of one of these right now” kind of beautiful. All skeleton AP Royal Oak Perpetual Calendars without leap-year indicators fall within this reference (skeleton watches with leap year have the reference 25829).

When I use the term “skeleton” I mean that the normally solid dial has been replaced with a sapphire unit that allows you to see the incredible levels of finish that AP applies to all parts of the movement, including those normally never seen.

All in, there were 264 examples of this watch made. 126 in yellow gold, 52 in stainless steel, 49 in two tone, 34 in platinum and three in rose gold. Two-tone watches include a rose-gold watch with a platinum bezel and platinum middle links, and a steel watch with a platinum bezel and platinum middle links.

To me, these are THE most beautiful and collectable of the non-leap-year indicator watches. They are also, based on examples made, the rarest. Another unique watch was made in yellow gold with the reference 25651.

The Third-Series Ref. 25654

Finally, either in the late ’80s or early ’90s, Audemars Piguet released another batch of Royal Oak Perpetual Calendar watches without leap year under the reference 25654. Some very beautiful watches emerged under this reference. If you find a pre-1995, non-leap-year RO Perpetual Calendar with a clous de Paris or hobnail dial, it should fall into this reference.

Watches were made in 272 examples in steel, 422 in yellow gold, 33 examples in platinum and just one in white gold. In addition, 72 examples were two tone, including this watch in a lovely combination of platinum with rose gold (the inverse of the beautiful 25636 two-tone model).

However, they were primarily made with the smooth dial. Incidentally, here is an image of the coolest 25654ST I’ve seen, which is a completely tropical-dial version.

In all, there were 1,630 non-leap-year watches made, including the references as follows: first-series ref. 5554 (25554), second reference with skeleton dial ref. 25636, and third reference ref. 25654. There are further two oddball gem-set examples made, one under reference 25624 and one under 25651.

You may have noticed that the prices of these early-reference non-leap-year Royal Oak Perpetual Calendar watches have almost tripled in the last four years. Why is that? Well, for one thing, since the launch of the Royal Oak Ceramic Perpetual Calendar in 2017 in both solid dial and skeleton versions, and the launch of 2019’s amazing Self-Winding Perpetual Calendar Ultra-Thin based on the 2018 RD#2 experimental watch, Royal Oak Perpetual Calendars have become one of the hottest watches around with the lifestyle crowd. The second reason is that with just 1,630 examples made during the 1980s and ’90s, people are coming around to just how rare these watches are. A third reason is that they are made in such variety it is easy to hone in on the rarity of specific references. The fourth and arguably most important reason is that vintage dealers — in particular those in Italy that set market trends — got together and decided to take a position in them, which started to ramp the prices up.

Is this wrong? Not necessarily, because prices will inevitably bear whatever the market decides. This is certainly not without precedent. Why do you think that Zenith-based Daytonas in the R series, especially the porcelain-dial versions, are way north of 100,000 dollars, or why Paul Newman Daytonas in general are the price that they are? Because these same dealers decided to make them cost this much and consumers were willing to feed the escalation. And the fifth reason is that as the union of the Royal Oak’s design with the iconic 2120/2800 movement, these watches are of tremendous historical significance.

That aside, the Royal Oak Perpetual Calendar is a genuinely amazing watch, and totally and utterly unique as an ultra-thin, complicated integrated bracelet, sports chic watch from the ’80s. Indeed, it would take Patek until 2018 to respond with a Nautilus Perpetual Calendar and it is 8.32mm thick.

Part II
The Leap-Year Indicator Returns, 1995–2015

In 1995, to celebrate the 120th anniversary of the maison, Audemars Piguet released the reference 25810 (or 25810.OR.01 to be exact) with caliber 2120/2802. This was a stunning rose-gold Royal Oak Perpetual Calendar with one major difference: the reappearance of the leap-year indicator. This took the form of a hand that was mounted coaxially with the month hand in the subdial at 12 o’clock. As a nice touch, the leap-year cycle is described in exactly the same font as that in the second-series 5516 watches. To me, this is one of the most historically significant and attractive executions of the RO Perpetual Calendar.

Reference 25686

Now in 1996, reference 25686 was launched. It is important to note that these are the LAST of the non-leap-year indicator watches. Why did AP launch this reference a full year AFTER the model with the leap-year indicator was introduced? Well, it’s possible that they had some 2120/2800 movements left and decided to use them for this final series of watches.

The 25686 has a wild and libidinous variety of dials and executions. I’ve seen a lot of colored mother-of-pearl watches but also watches with smooth dials, hobnail dials and even Tuscan dials. These watches included another two-tone stainless-steel and platinum version, a full stainless-steel version, a two-tone platinum and 18K rose-gold version, and a full platinum one.

OK, this is interesting if you have a smaller wrist or you’re a woman in the market looking for a value-proposition complicated AP. In 1997/98, AP launched reference 25800 with a diameter of 33mm in different metals and, for the first time, in white gold. This is in many ways an oddball watch as it was created ostensibly for the ladies’ market, but also for men with smaller wrist sizes. Because of its size, it is considerably less expensive than its full-sized brethren.

Reference 25820

In 1998, the reference 25820 made its appearance. This is when the 2120/2802 with leap-year indicator movement first seen on the limited edition 25810 enters regular production.

The Royal Oak Perpetual Calendar ref. 25820 was available with five dial variants in stainless steel (smooth silvered dial, white tapisserie and three different hues of blue with tapisserie as well), two dial variants in 18K yellow gold, two in platinum, three in stainless steel with platinum, and perhaps the most coveted of them all, a tantalum and rose-gold version, a tantalum and yellow-gold version, and the king of all Royal Oak Perpetual Calendars, the tantalum and platinum version. One of the most sought-after versions of this watch is the platinum salmon-dial version.

In 1998, the reference 25820 made its appearance. This is when the 2120/2802 with leap-year indicator movement first seen on the limited edition 25810 enters regular production.

Reference 25829

In the 1990s as well, the reference 25829 was launched marking the return of the skeleton dial in stainless steel, platinum, 18K yellow gold, 18K rose gold, and once again, the three incredible tantalum combinations with platinum, rose gold and yellow gold. To me, the tantalum two-tone versions of the watch would be amongst the most sought after! This version of the watch in steel is worn by my friend Mo Coppoletta. I’ve always thought his artistic personality, paired with his deep technical knowledge on watches, makes him the perfect person to own one of these watches.

Reference 25930

In 1999, AP brought the serious bling with 25930PT, a platinum Royal Oak Perpetual Calendar with factory diamond-set bezel and openworked dial.

Reference 25865

Reference 25865 falls a bit outside of the lines. While this watch also features a perpetual calendar, the movement is significantly different. This grand complication was created at Audemars Piguet Renaud & Papi, the high complication specialists that also make the movements for Richard Mille’s tourbillons and rattrapantes.

Launched in the mid-’90s the 25865 features a split-seconds chronograph, minute repeater and a perpetual calendar. The perpetual calendar module base on its display does, however, seem to be the Dubois-Dépraz module from the 2120/2800 just flipped 180 degrees and with the hands for continuous seconds and chronograph elapsed seconds added coaxially to the horizontal subdials. There would be several other grand complication Royal Oaks made but as these watches are not 2120/2800 related, I’ll leave them for now.

In 2008, AP launches the reference 26252 on leather straps. No real big news here, the Royal Oak perpetual calendar gets a leather bracelet option. Which honestly to me is not my favorite reference as the watch was born to be an integrated bracelet icon.

Part III
The Modern Era of the Royal Oak Perpetual Calendar, 2015–2020

Whew. Still with me? OK, go mix yourself a Negroni, light your cigar and let’s get into the modern era of the Royal Oak Perpetual Calendar. In 2015, the reference 26574 featuring the caliber 5134 marked the first major advancement of the legendary Audemars Piguet Perpetual Calendar housed inside an all-new case that measured 41mm in diameter as opposed to the traditional 39mm. Rather than 3.95mm, the movement is now 4.31mm thick. Why? Because of the addition of a week indicator. AP, however, did a great job in ensuring that the case of this watch is only marginally thicker at 9.5mm as opposed to 9.3mm of its predecessor.

The week was read using a centrally mounted hand off a scale located at the very perimeter of the dial (a nice nod to the date indicator on the 5516). This is apparently useful for people that work in finance for financial planning, which I’ve always found amusing as recognizing the decidedly playboy-like leaning of most AP owners, I would imagine them to all have teams of accountants supporting them. The enlarged case size actually finds its precedent in 2012 when AP changed the size of the standard Royal Oak from 39mm to 41mm. That year, however, it also introduced the 15202 Royal Oak Ultra-Thin in a size almost identical to the original 5402 (albeit slightly thicker because of the sapphire caseback).

The Royal Oak Perpetual Calendar Ceramic Ref. 26579CE

2017 marks the year when the Royal Oak became a serious trophy watch because the manufacture unveiled the all-ceramic perpetual calendar. Incredibly, every single part of the watch was brushed and polished to the high standards of AP, making it remarkably distinct from the majority of ceramic tool watches on the market.

It also attracted a whole new clientele, collectors who would normally be Richard Mille or, in previous years, Royal Oak Offshore collectors and liked the fresh injection of modernity to the watch. At the same time it also managing to strike a chord with serious horophiles and as a result, the limited production timepiece became one of the hottest commodities in the world. Here is an image of American actor Kevin Hart wearing his AP Royal Oak Perpetual Calendar to give you an idea of the clientele that AP began to attract with the ceramic watch.

The Royal Oak RD#2, 2018

Much of the excitement around the 2018 Salon International de la Haute Horlogerie (SIHH) focused around a watch that you couldn’t buy. This was the Audemars Piguet RD#2, which stood for Research & Development 2 (the first RD forged the basis of the brand’s badass super sonnerie.) The new watch was the brand’s take on a Royal Oak Perpetual Calendar but now ultra-thin. How thin, you ask? Incredibly thin actually. At 41mm in diameter and 6.3mm in thickness, the watch was almost a full millimeter thinner than the time-and-date-only 5402 — the 7.2mm-thick watch that kicked things off back in 1972.

How did AP achieve this? Actually, very much in a beautiful act of homage to the original 2120/2800, created by team RGB, otherwise known as Rochat, Golay and Berney. At the base of the watch was the same 2120 caliber, which has been such a key part of Audemars Piguet’s seismic horological audacity throughout the late 20th century and into the third millennium. However, the calendar mechanism was significantly changed.

First, rather than a module, all the perpetual calendar works were integrated into the base of the caliber 2120. Second, we saw some major distribution of movement across a horizontal plane which made the movement larger; instead of 28mm, the movement now had a diameter of 32mm. And this also accounts for a change in placement of some key indications. Moonphase was now at 12 o’clock, with months at three o’clock, date at six and day at nine o’clock.

The key change, however, was that leap year did not sit coaxially with the months but appeared in a small subdial at four o’clock, while a similar dial for day-and-night indication (key for not setting the perpetual calendar during the changeover period) was at eight o’clock. The result is a movement that is a mere 2.89mm thick as opposed to the 3.95mm thickness of the caliber 2120/2800 or the 4.31mm thickness of the caliber 5134. After teasing us into a lust-filled lather, AP sent us packing empty-handed explaining that RD#2 was strictly a concept watch, but CEO François Bennahmias said it with a twinkle in his eye.

Reference 26586

AP’s last SIHH in 2019 and as it turns out the last SIHH of all time — the fair has since been rechristened Watches & Wonders Geneva for 2021 — heralded a seminal year for Audemars Piguet, which saw the launch of two of its most sought-after perpetual calendar watches. These were the commercial version of the RD#2 known as the Royal Oak Self-Winding Perpetual Calendar Ultra-Thin as well as the new openworked ceramic Royal Oak Perpetual Calendar. It should be noted that a new-case-style CODE 11.59 was also launched that year with a perpetual calendar version in an appealing aventurine dial.

Don’t say Audemars Piguet doesn’t give the people what they want. After teasing us with the RD#2 concept watch in 2018 and then sending us to the brink of despair with the “will they/won’t they?” anxiety, they finally set our minds at ease and made our wallets 140,000 Swiss francs lighter — that is, if you can get one — with the incredible reference 26586, the production version of the RD#2. The first thing that was appreciated was the material of choice, which was titanium with the addition of a platinum bezel and middle links. The RD#2 had been made from full platinum and it was the weight of a small boat anchor.

Reference 26585

The reference 26585 Royal Oak Perpetual Calendar Openworked Ceramic was another staggering hit for the brand in 2019. By uniting two of it signatures, the use of black ceramic and openworked dials, AP created another horological sensation with this model. The use of rose-gold accents and the unrestricted view of the fantastic levels of finish on the movement create an altogether different watch than previous versions of the watch.

Reference 26579

Reference 26579 is a Royal Oak Perpetual Calendar in white ceramic. Because, why not? As my friend Mo Coppoletta explained, “[Pair] this watch with a blinding white Speedo and you will be the king of the Italian Riviera.” Clearly he meant this with some levity, but the point is that the most successful watch brands have immense horological merit and yet have transformed themselves into lifestyle brands. This white ceramic perpetual calendar is a perfect expression of AP’s success in this evolution.

And with that, we end the story of the amazing, iconic Audemars Piguet Royal Oak Perpetual Calendar. But hang on, because the work of Rochat, Golay and Berney can also be found in one strange, unlikely and incredibly cool watch: the Royal Oak Offshore Perpetual Calendar.

The Royal Oak Offshore Perpetual Calendar Ref.25854BC, 1997

In 1997, Audemars Piguet launched what I consider to be one of the coolest perpetual calendar watches of all time, in a case that at first might seem counter-intuitive. OK, let’s hark back to 1993. When in collaboration with a cool young maverick watch designer, Audemars Piguet shocked the world (by this time something of a signature for these masters of audacity) with a watch that had many an erudite and refined horological collectors spilling their cups of tea in their laps. The name of this timepiece was the Royal Oak Offshore, perhaps more accurately described by its sobriquet, “The Beast.”

The designer in question, one Emmanuel Gueit, had been trying for some time to convince Georges-Henri Meylan, then CEO of Audemars Piguet, to greenlight his project. Which was essentially to take Genta’s elegant design for the Royal Oak and seemingly inject it with growth hormones so that it swelled up to what could only be described in the context of the ’90s as behemoth-like proportions. At a massive 42mm, the integrated bracelet chronograph was not so much a sports watch but a personal defense weapon, albeit one finished to typical sublime standards.

Eventually, Meylan acquiesced to Gueit’s constant requests and decided to launch the Offshore with the expectation that it would be a flop. Instead, the watch became a rampaging success with one early adopter in particular, none other than the “Austrian Oak,” Arnold Schwarzenegger.  One of Hollywood’s biggest stars at the time, Arnold even had special editions of the Offshore made for two of his films, End of Days and Terminator Three: Rise of the Machines. The resulting watches were the all-black Offshore with yellow accents for End of Days and the crazy, oversized T3 Offshore with knuckle-duster-like protectors for the chrono pushers, would become two of the most iconic watches of this hyperbolic era.

The Offshore soon became synonymous with a type of larger-than-life personality. For the next 15 years, the Royal Oak Offshore became the single most desirable oversized sports watch in modern watchmaking history and was worn by the likes of everyone, including Jay-Z and LeBron James, both of whom had limited editions of the watch made for them, and Kanye West. Serena Williams’ affection for the watch is overtly demonstrated by the fact that she actually wears one while playing, as does Stanislas Wawrinka.

If you want to read more about the history of this model, read this excellent article by my friend Arthur Touchot from Phillips Watches.

In 1997, Audemars Piguet created a perpetual calendar chronograph version of this watch. This model features prominently in the collection of renowned watch expert Alfredo Paramico. The idea behind the watch actually makes a lot of sense. It has been explained that the original caliber 2120/2800 resulted from the collaboration with complication specialist Dubois Dépraz. When it was time to equip the Offshore with the movement, in order to keep it related to the original Royal Oak, the decision was made to use the fantastic caliber 2121. However, what happens when you have a movement that measures 3.05mm in thickness in a case that measures 14.90mm in thickness? Well, you have a lot of space. In order to make the watch more aggressively sporty, the decision was to make it a chronograph and ultimately, AP landed on the solution of placing a chronograph module on top of their beloved ultra-thin caliber. Who did they decide to work with to create this complication? None other than Dubois Dépraz.

But when they did, they realized that the distance from the dial to the date wheel of the watch was so extreme that it was impossible to see the date. Rather than imagining this to be a hindrance, Gueit turned it into a signature design detail by adding an inverted loupe to the dial to magnify the date. Eventually, the watch even received a soft iron inner shield, allowing AP to proclaim the watch amagnetic. But even then it stands to reason there was still some amount of space in the case, more than enough to also place the perpetual calendar module inside, which also happened to be made at Dubois Dépraz.

The stunning Offshore Perpetual Calendar Chronograph was made in several different versions. In 1997, AP launched the white-gold version with blue dial — the 25854BC which is perhaps the ultimate stealth watch. In looks, it is almost exactly like the steel watch but it weighs the equivalent of a boat anchor. This is followed in 1998 by the steel blue-dial version reference 25854ST, and then in 1999, the watch in rose gold, the 25854OR. Finally, in 2003, a white-dial titanium version is released — the 25854TI. The dial of this super complicated machine was laid out in the following way: Both continuous seconds and date shared the subdial at 12 o’clock, phases of the moon in the subdial at three o’clock, both day and chronograph in the 12-hour counter in the subdial at six o’clock, and month, chronograph minute counter and the leap-year indicator all within the subdial at nine o’clock.

Is it crazy to have a refined complication like a perpetual calendar in a watch that looks more like a personal defense weapon? Well, it’s just this entertaining contrast that has been the hallmark of Audemars Piguet and, without this daring, it would not have launched and dominated the perpetual calendar field with such style as it has over the last half century.

So ends our 10,000-word journey through the history of one of my favorite brands, Audemars Piguet, and its audacious thrilling journey with the perpetual calendar. I hope you’ve enjoyed reading this as much as I’ve enjoyed writing it. With the value of these watches very much on the rise, I thought it important to chronicle all the different references. However, if I’ve missed out any, please e-mail us at [email protected] and we will add it in.

Post script
Jules Audemars / Code 11.59 Perpetual Calendars

Lastly, and for the sake of this article’s completeness, let’s take a brief look at the Jules Audemars Perpetual Calendar watches. These came in an automatic perpetual calendar version, a perpetual calendar chronograph version, a perpetual calendar with equation-of-time version that displayed the difference between solar time and civil time with an equation-of-time cam that was synchronized to the perpetual calendar version, and even a grand complication version with perpetual calendar, minute repeater and chronograph. While these watches are not as historically significant as the extra-thin perpetual calendars such as the 5548 and the Royal Oak Perpetual Calendars launched in 1984 with the reference 5554, here is a look at the various different versions made over these models’ lifespan, which ended in 2017 to give way to the new CODE 11.59 which also comes in a perpetual calendar model featuring the caliber 5134.

About the Pygmalion Gallery

The Pygmalion Gallery takes its name from the mythological ancient Greek sculptor, Pygmalion who is said to have carved a woman out of ivory of such beauty and purity that he was compelled to uttered a prayer under his breath at altar of Aphrodite, wishing to have his sculpture come to life so that he might marry her. His love was so profound, that Aphrodite granted his wish.

Like the legend, Pygmalion Gallery honours the beautiful creations born by talented human hands, and is where yesterday’s masterpieces come to life. It is based in Singapore, and has one of the most extensive collection of vintage Audemars Piguet timepieces in the world. Inspired by the love of beautiful things, the gallery also curates an exclusive catalogue of vintage AP watches, jewellery, and art objects for like-minded clients.

www.pygmaliongallery.com
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