L ike a Bugatti coupé or a Bang & Olufsen speaker, great watches are judged on both form and function. These are objects in which what isn’t seen is as impressive as what’s on the surface. Crafting the engine of a watch requires just as much, if not more, artistry than the case in which it’s housed. Complications—essentially, whatever a timepiece can do in addition to telling the time—are the true test of a watchmaker’s skill. Of all the complications a watch can have, from displaying the date to calculating multiple time zones, the perpetual calendar is one of the most challenging technical feats a watchmaker can achieve. And when it comes to perpetual calendars, there is one undisputed master: Patek Philippe.
What is it about perpetual calendars that inspires such reverence? For those that aren’t well-versed in horological lingo, a bit of explanation: according to the Gregorian calendar (which most all of the world abides by), there is a leap year every four years. Without getting too deep into astronomical theory, the addition of an extra day (February 29th) every four years compensates for the discrepancies between time as we calculate it (i.e. 24 hours in a day, 365 days in a year, etc.) and the actual cycle of the earth’s revolution around the sun. Perpetual calendars account for this somewhat curious rule, effectively measuring the time, day and month in perpetuity without requiring any adjustments.
All of this may sound like rather unsexy technical minutiae, but it is a truly remarkable piece of engineering. Think of it: a system of springs and rotors that knows which month has 31 days, which has 28 and sometimes 29, all without anything other than winding. At a time when our phones automatically dim once the sun sets, it can be hard to appreciate what a seismic breakthrough the perpetual calendar was—even more so, considering that it was invented almost 60 years before electricity and almost 125 years before the first car. In some views, the perpetual calendar laid the groundwork for computers as we know them today.
Patek Philippe may not be able to take credit for inventing the perpetual calendar—that honor goes to English watchmaker Thomas Mudge, who pioneered the technology in 1762—but the Swiss firm perfected it. After Mudge’s breakthrough, no other watchmaker could replicate the intricate movement until 1864, when Patek Philippe created a perpetual calendar pocket watch. Ever striving for refinement, the brand evolved the movement and scaled it down to power a ladies’ pendant watch in 1898. While undoubtedly an exquisite timepiece, the pendant proved to be a tough sell—the market for women’s watches at the time didn’t have a huge audience for cutting edge precision (but kudos to Patek for offering it).
So it wasn’t until 1925 that the same movement, having gone unsold, was re-cased in a 34.4mm yellow gold case and the world’s first perpetual calendar wristwatch was born. It’s worth noting the relatively small 34.4mm case. What makes a perpetual calendar so useful, and so challenging to create, is that it calculates much more that the hour and minutes—seconds, date, day of the week, month, moon phase—and each of those additional calculations requires its own set of mechanisms. That Patek Philippe was able to cram all of this into a watch that wasn’t notably larger than its simpler time-only brethren is a testament to the brand’s engineering prowess.
Upcoming Patek Philippe Perpetual Calendars at Auction
That first perpetual calendar wristwatch, ref. 97975, featured four sub-dials indicating the seconds, day, moon phase and month, while the date was displayed via a scale along the dial’s perimeter. This layout would be refined in subsequent perpetual calendar variations, like the ref. 96 released in 1937. Patek Philippe may be best known for its elegantly understated Calatrava line—in many ways, a model that set the template for modern dress watch design. The firm is synonymous with a certain breed of exquisite restraint, and the ref. 96 is a prime example of Patek’s knack for making complex movements look effortless. This visual simplicity remains a hallmark of the brand’s grand complications to this day.
In lieu of numerous sub-dials, which can yield a somewhat messy appearance, the ref. 96 introduced two parallel aperture windows for the day and month. Its biggest breakthrough was employing the first ever retrograde date display: rather than a circular sub-dial looping from 1 to 31, the date was arranged as a semi-circle along the top half of the dial, indicated by a blued retrograde hand that, after midnight on the last day of the month, instantly jumps back to 1. Retrogrades, now utilized in a number of different complications, are indebted to this thoughtfully-designed perpetual calendar.
In retrospect, the retrograde can seem like a footnote in Patek’s rich lineage of perpetual calendars. The innovations just kept coming. One of the most important years was 1941, which saw Patek debut two watches that are legendary in the annals of horological history. The ref. 1526 was the world’s first serially produced perpetual calendar and a game-changer for the industry. While today, complicated watches are a staple of any respectable watchmaker’s collection, back in 1941 complications were an exclusive rarity reserved for private commissions. The ref. 1526 upped the ante by introducing a complication (a perpetual calendar, no less!) into the lingua franca of watches for general consumers.
The other big debut, the ref. 1518, was pioneering from a technical standpoint: the world’s first serially produced perpetual calendar and chronograph. It was a mind-boggling feat of engineering—combining all the data of a perpetual calendar with the stopwatch capabilities of a chronograph—that no other maker would even attempt for another 50 years. Perpetual calendar chronographs remain a specialty of the brand and are considered by many collectors to be the ultimate expression of Patek Philippe’s technical mastery and aesthetic refinement.
One of the most sought-after models, the ref. 2499, fetched CHF 3.9 million at a Sotheby’s Geneva sale in 2018. Prior to that, the record was held by a ref. 2499 owned by rocker Eric Clapton, which sold for $3.65 million. If there was any doubt as to the value of a Patek Philippe perpetual calendar, just consider the Grandmaster Chime—the brand’s most complicated wristwatch ever produced, boasting 20 different functions including a perpetual calendar and minute repeater—which sold for $31.2 million in 2019 and holds the record for the most expensive watch ever sold.
Patek Philippe Perpetual Calendars Previously Sold at Sotheby's
While perpetual calendars feature in many of Patek Philippe’s rarest, one-of-a-kind timepieces, the brand has often produced perpetual calendars as elegant everyday watches. One celebrated model, the automatic ref. 3940, is rumored to have been former CEO Philippe Stern’s watch of choice. That design was eventually replaced by the ref. 5140, employing an even thinner self-winding movement, and finally by the ref. 5327, which added a sleek Calatrava style case and Breguet Arabic numerals. Launched in 2016, it is the flagship perpetual calendar in Patek’s collection today. And as of 2018, the ref. 5740 combines another G.O.A.T., the sporty Nautilus, with this haute complication—proof of the perpetual calendar’s stylistic range.
In any iteration, Patek Philippe’s perpetual calendars carry a unique significance for watch connoisseurs. The complication encapsulates the history of horology, from Thomas Mudge’s day through to the introduction of complicated wristwatches and modern-day innovations. It can be argued that the perpetual calendar is the pinnacle of the watchmaker’s craft, and Patek Philippe’s are the apotheosis of everything that makes it one of the most esteemed brands in the world.