The Complete History of the Audemars Piguet Perpetual Calendar

The complete history of the Audemars Piguet Perpetual Calendar is written by Wei ‘Le Wei’ Koh, in collaboration with Michael ‘Le Mic’ Friedman and Pygmalion Gallery, with thanks to Tom Chng.
An excellent example of the Second-Series ref. 5516 with the leap-year indicator at 12 o'clock, sans the 48-month scale; the watch seen here is presently part of the Pygmalion Gallery's private collection (Image: Photo and watch, property of Pygmalion Gallery)


Wild, Iconalistic, 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)

These 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.

1762 - The World's First Perpetual Calendar Timepiece



"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.

1875 - Jules Louis Audemars’ School Watch

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.



Image Close up of leap-year display

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.


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.

Comparing the Patek 2497 with AP's 5516

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 and 1969.

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.


August 2020


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