Thierry Stern, the leader of the most respected high watchmaking manufacture on the planet — Patek Philippe — is in a good place creatively. By now, every devotee of the horological arts knows the story of how he was given the challenge to design the replacement for the iconic Ref. 3970 Perpetual Calendar Chronograph by his father, the legendary Philippe Stern. The watch he created, the Ref. 5970, surpassed even his father’s loftiest expectations. Launched in 2004, it is to my mind the most beautiful watch ever made that features these two complications together. Eighteen years and innumerable watches later, Thierry Stern recounts the following story with a smile, “Picasso was known to be able to draw a perfect circle in one continuous line. (An act that was an homage to Tuscan painter Giotto di Bondone.) He would amaze people with this act of skill. One day, someone said to him, ‘It’s incredible that you are able to draw this perfect circle in just a few seconds.’ Picasso responded, ‘What you see in front of you is the circle. What you don’t see is the 40 years that it took for me to get here.’ I’ve been designing watches now for 30 years at Patek Philippe — originally together with my father and eventually on my own. I’ve reached a point where I really enjoy the process. It comes naturally now but only after decades of work.” And he gestures — naturally — to the stunning new Patek Philippe Ref. 5326 Annual Calendar Travel Time.

Look at the watch in question, the Ref. 5326, and your brain will start firing into overdrive, such is the vast array of appealing details you are suddenly taking in at once. The dial is utterly unique in the history of Patek, and the first question that comes to mind is where this decoration came from. The style of the hands and indexes as well as the shape of the case are all subtle nods to Patek’s history. Then, there is the ravishing Clous de Paris pattern engraved into the side of the case and which magically seems to flow under the sharply angled lugs. Finally, there is the notable absence of any alligator strap; this is replaced by not one but two decidedly modern calfskin straps — a beige option with nubuck finish and a black version with embossed textile finish and beige decorative stitching. Taken in totality, the watch feels incredibly modern, as if it is announcing a new chapter in Patek’s design philosophy.

Contemporary Tribute to the Calatrava

Says Thierry Stern, “To understand one of the key style codes of the new Ref. 5326, we need to go back to the development of last year’s Calatrava Ref. 6119. For some time, I wanted to create a new Calatrava, something that was a striking tribute to our heritage, but was also a watch that felt really contemporary and modern. I wanted a watch that, the moment you saw it, you recognized it. I found the answer when I thought of the Ref. 3919. This was a Calatrava watch that we launched in 1985 and it featured a distinct Clous de Paris, or Paris hobnail guilloché pattern on the bezel. We repeated this design in a slightly larger case in 2006 with the Ref. 5119. It is a really beautiful and distinct pattern, and so, in combination with a movement developed specifically for the new Ref. 6119, we created an all-new Calatrava.”

“When I was thinking about the design of this watch, I thought it would be very elegant and at the same time dynamic to add this pattern to the side or mid-case. But one issue was, of course, how you would integrate the lugs without disturbing the pattern. I wanted to see the Clous de Paris flow uninterrupted right up to the lugs, which was not possible with soldered lugs or lugs that were part of the mid-case. So we got the idea to attach the lugs to the caseback instead, so that the hobnail pattern actually continues underneath them. I like the idea that in the future when a watchmaker disassembles the watch for a service, he will remark on how perfectly finished all the parts are that are not visible to the eye. To me, this is very Patek.”

Regarding the most unusual striking dial, Stern says, “I knew I needed some kind of decoration for the dial. I didn’t want to just keep it black, because I wantedthe watch to really express great nuance in details. One evening, I was over at a friend’s house and noticed his collection of vintage cameras. There was this texture on the camera bodies which provides them with grip, but I thought that it was very beautiful. I went to Fluckiger Cadrans, the dial factory that we own, and we started on experiments to get this texture right.”

The shape of the case is also distinctly Patek and brings to mind the Ref. 5236, the world’s first in-line perpetual calendar wristwatch launched last year, which inverts the two middle numbers of the brand’s numerical designation code. The Annual Calendar Travel Time, of course, has slightly thicker lugs that befit a sportier watch. With this style of case, the iconic Ref. 3448 comes to mind and it is heart-warming to see that with Patek, there are always small connections with the past.

The case is dynamically charged with the use of straight angled lines for the lugs, which presents a stark contrast against the round and flat bezel. The hobnail motif in the caseband as well as the rough but elegant dial treatment creates a visually enticing and energetic watch. In addition to the shape of the watch, it also features two of the Manufacture’s recognizable design codes. These are the syringe-shaped hands that were featured on the chronograph model Ref. 5172 and which came from the perpetual calendar model Ref. 5320. As an aside, both of these watches are the recipients of a makeover this year in the form of the rose-gilt opaline dial models, and the results are stunning to behold. These hands were famously inspired by the Ref. 1591, a unique perpetual calendar made in steel that was waterproof. The story goes that it was created for a famous and sporty Indian maharaja who wanted to use his complicated watch in all conditions. Notably, these syringe-style hands were luminous in this early use.

On the subject of luminosity, the new Ref. 5326 features beige colored Super-LumiNova that is similar in color to the vintage aged radium found in the Ref. 1591 manufactured in 1944. This is an interesting choice as there has been, for some years, a debate over the appeal of intentionally coloring luminous indexes and hands to look as if they were aged. Some feel that this was something of a trend that has passed while others like it. Personally, I feel that it depends entirely on the design of the watch. In the case of the Ref. 5326, because of the texture of the dial, the style of the hands and the Clous de Paris decoration in the case, it works perfectly. Says Stern with a chuckle, “Yes, we had the same internal debate regarding the color of the indexes and hands. But finally, when we tried out this beige color, I said, ‘That’s the one.’ It just works.”

Patek Philippe Travel Time

What about the unique complications offered by the watch? Well, in fact, you could say the new Ref. 5326 represents the first meeting between two of Patek Philippe’s most legendary innovations. These are the multiple time zone function known as the Travel Time as well as the famous Annual Calendar invented by Thierry Stern’s father, Philippe Stern.

Let’s start with the Travel Time function. Look at the dial and you’ll see two apertures at the bottom right and left. The aperture on the right is a day and night indicator for home time and the aperture on the left shows day and night for local time. How the watch works is like this: The hour hand actually features a second home time hand that is positioned underneath it and is not visible when they run together superimposed. In a normal Travel Time watch, you have two pushers located at the left of the case, which you use to advance the local hour hand in either direction. With each push, the local hour hand (the traditional hour hand) jumps forward by one increment but without affecting the underlying time telling of the watch. Which means the hour hand is decoupled from the gear train during these jumps. You will, however, notice the conspicuous absence of these pushers in the Ref. 5326. And that is because Thierry Stern didn’t want to mar the beauty of the case he had created. Instead, the Travel Time function is controlled via the crown of the watch and is adjusted in position two. You will see as the local hour hand is advanced, a beige home time hour hand is left behind. The first-time integration of the Travel Time function into the crown happened in 2021 with the Aquanaut Luce, and the Ref. 5326 is only the second watch to feature this function.

While today there are many watches that tell two time zones, you need to understand how innovative this complication was when it was launched in the late ’50s. At this time, Patek’s multi-timezone watch was its World Timer. This amazing watch used a system for reading time simultaneously in 24 zones devised by a brilliant watchmaker named Louis Cottier. However, by the era of jet travel, Patek Philippe was clearly aware that while the World Timer was, in some ways, going out of fashion, there was definitely a demand for a rapidly adjustable travel-specific watch. By 1958, Henri Stern (Philippe Stern’s father and Thierry’s grandfather) who had set up Patek Philippe’s agency in the United States would become the president of the manufacture. He was an inveterate traveler and understood the type of watch that someone with his lifestyle could benefit from. As he had spent his formative years in the United States, he had witnessed the surging spirit of American modernism. The same year he ascended to his place as the head of Patek, the big news was that the first commercial flights between London and New York had begun. He and his team approached Louis Cottier to design the Travel Time. This was a timepiece that had all the elegance and charm of Patek’s famous Calatrava line but that allowed rapid setting in either direction of the hour hand to a new zone. In the late 1950s, Patek Philippe unveiled that watch known initially as the “Cross Country.” The Ref. 2597 featured two pushers subtly integrated into the left of the case that would advance the hour hand either backwards or forwards with a single jump without affecting the underlying timing accuracy of the watch.

Interestingly, the movement selected was a modified Caliber 12-400, the 12-400 HS (Heures Sautantes or Jumping Hours). This movement featured a single hour hand which jumped positions. Quickly after the release of the first Ref. 2597, another version was introduced with two hour hands that ran superimposed on top of each other when you were not traveling. But as soon as you reached a new zone, the hour hand could be decoupled from the other hands and made to jump so as to tell time in a new zone, leaving the other hour hand to provide the time in your home city. The Travel Time would go on to be one of Patek Philippe’s most successful watches with that complication finding its way into other models, including the much sought-after Nautilus Travel Time Chronograph and the Aquanaut Travel Time. It also must have shown Cottier the practicality and appeal of a pusher system that controlled an instantaneous jumping function. According to Patek lore, this gave him the idea to update and improve his World Time watch so that the hands, the 24-hour ring and the city disk would all jump to the correct positions with the single depression of a pusher. Patek Philippe even registered a patent for this mechanism. But that movement would not see the light of day for another 35 years as Cottier passed away in 1966.

The Travel Time has become as synonymous with Patek Philippe as the perpetual calendar and the perpetual calendar chronograph — both complications that the manufacture introduced to the world with Ref. 1526 and Ref. 1518, both from 1941. I would remark that while there are indeed many multi-timezone watches in existence today, few rival the practicality of the Travel Time display with double day/night indicators for local and home time.

Patek Philippe Annual Calendar

The other complication that Patek is equally well known for is the Annual Calendar. The year 1996 was an extraordinary year for Patek Philippe. It united all of its watchmaking competences under one roof in Geneva’s Plan-les-Ouates, and Philippe Stern launched the famous Annual Calendar. He was undoubtedly proud of the fact that Patek had introduced the perpetual calendar wristwatch to the world just over 70 years before. But he also wanted his tenure at the head of Patek to be marked by real innovation.

Before embarking on a little history of the Patek Philippe Annual Calendar, let’s first define what a perpetual calendar is. Ever wondered where our calendar system came from? It was all down to a pope named Gregory XIII who, in 1582, instituted the Gregorian calendar, which corrected faults in the Julian calendar. The issue essentially was this: The calendar year where time is divided into 24-hour days, seven days a week and 30 or 31 days a month with 28 days in February for a total of 365 days, is actually shorter than the solar year, which is how long the Earth takes for a full rotation around the Sun — 365 days, five hours, 48 minutes and 46 seconds, to be precise. To compensate for this, Pope Gregory XIII added the day of February 29th once every four years. But this in turn creates a slight overage so that every 100 years, though divisible by four, the leap day is left out. Every 400 years, it is put back in.

Still with me? OK. So to put a perpetual calendar mechanism which would keep track of the date, day, compensate for the shifting 30/31- day cycle of the months, know when February had 28 days and know when it had 29 days, would be an act of horological badassitude in extremitas, correct? Well, it just so happened that an English watchmaker named Thomas Mudge did just that in 1762. In 2016, that watch went up for auction and was purchased by none other than the most famous watch brand on the planet, Patek Philippe. This was extremely fitting because in the annals of modern horology, there is no brand more synergistically associated with the perpetual calendar wristwatch. Patek Philippe was the very first — to create a perpetual calendar wristwatch in 1925, a retrograde perpetual calendar wristwatch in 1937 and a perpetual calendar wristwatch in series in 1941 with the legendary Ref. 1526. It was the first to create a sweep seconds perpetual calendar wristwatch in 1944 with Ref. 1591 and to serially produce this complication in 1951 with Ref. 2497. It was also the first to create a self-winding perpetual calendar beginning in 1962 with the iconic Ref. 3448; it would take a full 16 years before another Swiss watchmaker could match this achievement. In addition, Patek was also the first to create a perpetual calendar chronograph in 1941.

OK, now let’s flash forward to 1996. Why was the Annual Calendar so significant to Patek Philippe? In the context of the time, there was a growing gap between a Patek Calatrava which cost under USD 10,000 and their perpetual calendar models, which start from USD 45,000. It was clear to Philippe Stern that there was a price segment between these two watches that Patek was not occupying. And yet this niche represented an important middle ground for a developing collector. The other important thing to understand is that a perpetual calendar is, generally speaking, a watch for a mature collector, as it needs to be operated in a certain way to ensure it functions correctly. Attempting to adjust the date while the watch is amidst the changeover function that happens between 9 p.m. and 3 a.m., for example, could result in a costly service. So the more Stern thought about it, the more he saw the need for a calendar watch that was user-centric. This made sense especially in appealing to a developing group of young customers. Finally, as the watch industry in general had just recovered from the Quartz Crisis in the previous decade, it also made sense that Stern would want to spread the love of complicated watches to the next generation of collectors.

What is interesting about the creation of the Annual Calendar is that it was presented as a challenge, or more specifically, a diploma topic at Geneva’s School of Engineering in 1991. The idea was to create a new calendar system that did away with the fragile racks, cams and jumper springs of a perpetual calendar and replace them largely with gear wheels. The system that was eventually arrived at, and that Patek would patent, featured as its core innovation a 24-hour driving wheel. This had two “fingers” at an angle to one another. Finger one advanced the date once a day. The second finger was put into use on transitions from months with 30 days to the 1st of the next month, allowing you to skip the 31st. The full changeover in this scenario took four hours to complete. Interestingly, when designing Ref. 5326, it was clear to Patek that a lengthy changeover period would not be acceptable in a multi-timezone watch with date function. More on this later. Anyway, the main simplification represented by the Annual Calendar is that it no longer had to predict the 48-month leap year cycle or add the additional day in February when the leap year occurred, saving substantial mechanical costs.

Launched in 1996, Ref. 5035 Annual Calendar, priced at under USD 20,000 was an instant hit. In addition to its use of luminous hands, a sporty case made it particularly appealing with a younger audience. It was an all-around success for Patek Philippe. On the 10th year anniversary of the Annual Calendar in 2006, the complication was placed inside the two watches that it is most associated with today. The first is the Ref. 5396, which when launched back in 2006, represented the first Calatrava Annual Calendar. And the second is Ref. 5960, a fantastic automatic vertical clutch chronograph with annual calendar, although one sleeper watch is the wonderful Nautilus Annual Calendar Ref. 5726.

Eight New Patents

The integration of the two famous complications in this brand-new Calatrava gave Patek the opportunity to improve their performance. As mentioned, Ref. 5326 is only the second watch to have the local time-setting function integrated into the crown, with the first being the 2021 Aquanaut Luce Travel Time.

Says Thierry Stern, “With this new Calatrava Annual Calendar Travel Time’s beautiful Clous de Paris decoration around the caseband, I didn’t want to add pushers which would interrupt this special decoration.” Instead, the crown has three positions for winding, setting of local time and semi-quickset for the date/calendar information, and setting of the time with local and home time synchronized, and with hacking function. To adjust for a new time zone, you simply move the crown to the middle position and turn the hour hand either backwards or forwards. In this position, the seconds continue uninterrupted and you can set your local time without affecting the overall accuracy of the watch.

Ref. 5326 also compensates for one important factor. Say, for example, you are flying from Singapore to New York. When you arrive in JFK Airport, you will set your watch 12 hours backwards. However, during the flight, you might have crossed the midnight threshold, meaning that the date and day of your arrival is actually previous to what is displayed on your dial. But never fear, because as you turn the hour hand in the opposite direction past the midnight threshold, the date and day displays (and months where affected) will also change back to the previous day.

That is not the only innovation represented by Ref. 5326. One of the wonderful things about Patek Philippe is that it is constantly improving its own watches. In the very first examples of the Annual Calendar, the changeover from 30th to the 1st took four hours to complete. In more recent versions, this changeover takes 90 minutes.

The problem is, of course, the question, what if you try to change your local time during this changeover period? A misalignment of the date and calendar information could occur. Right? Patek with its usual thoroughness recognized this and set about creating a mechanism that would make the date changeover five times faster. It now takes around 18 minutes to take place. This is down to a cam system with partial toothing connecting to the hour wheel. The 24-hour wheel now completes its rotation in four distinct phases — 180 degrees of rotation for three hours (toward midnight), nine hours of standstill, then another three hours of 180-degree rotation (toward noon), followed by another nine hours of standstill.

Patek explains that this improves the coordination of the calendar switching phase with local time. All in, the caliber 31-260 PS QA LU FUS 24H movement boasts a total of eight new patents. The first is for time setting with three crown positions. The system has a lever that actually deactivates “dead” wheels that are not performing any function so as to conserve energy. The second is the forwards and backwards setting function for the annual calendar, thanks to a tooth and spring on the month lever. This allows the watch to transition from the 30th to the 1st, and backwards from the 1st to the 30th, without desynchronizing the date. The third is for a linear time zone spring that increases the torque between the local time hour wheel and the home time hour wheel. The fourth and fifth are for two pivotable holding bridges that hold the day-date disks in position without the use of a center screw. The sixth is for an inertial delta that prevents an inadvertent misalignment of the time displays when the time zone is bring corrected. The seventh relates to a braking mechanism for the date disk when a correction is being made. The eighth is for flexible correctors. The flexibility of these leaf springs means that you remove the risk of material failure when a correction is performed during an unfavorable time window. Says Patek Philippe’s technical director Philip Barat, “We realized that people didn’t really want to read instruction manuals anymore. So we had to create a watch that blocked certain functions to prevent them from being incorrectly manipulated.”

Taken altogether, the design and technical innovations represented by Ref. 5326 makes it one of the most significant timepieces in recent memory.