Introducing: The Patek Philippe Ref. 5236P-001 In-Line Perpetual Calendar (A First For Patek)

Despite the fact that Patek Philippe has become best-known, in the past couple of years, as the maker of a somewhat quirky blue-dial stainless steel sports watch originally designed in the 1970s, it's worth occasionally reminding ourselves that they've been doing just a couple of other things for quite a bit longer, representing just a smidge more in terms of meaty horological content than the you-know-what and its successor. You might have thought that Watches & Wonders 2021 would be, at least for Patek, remembered as the trade show where that watch debuted, but today, Patek's announced a new piece that is, if not a return to form per se, certainly a firm and emphatic reminder that this revered Genevan firm did not achieve its exalted position in horology by feeding a fad machine, on the internet or otherwise. The new piece is the Ref. 5236P-001 In-Line Perpetual Calendar. It comes in a 41.3mm x 11.5mm platinum case, with a new movement, the cal. 31-260 PS QL. Patek enthusiasts will notice immediately the complete in-line display of the date, which is a first for Patek in a wristwatch; price at launch is $130,110. If there's a single complication with which Patek is most strongly identified, it's probably the perpetual calendar. The company produced its first perpetual calendar wristwatch, a unique piece, in 1925, and it has also done an in-line display perpetual calendar before as well – this, however (No. P-1450), was a pocket watch, which was completed in 1975 and which is now in the Patek Museum, along with the 1925 wristwatch. The first perpetual calendar wristwatch, and Patek's in-line perpetual calendar pocket watch. Images, Patek Museum. Producing an in-line perpetual calendar wristwatch, as opposed to a pocket watch, presents a number of challenges. The first is that it adds considerable complexity to what is already a pretty high-parts-count complication. The second is that it drains additional energy from the movement, thanks to the energy penalty incurred by moving the disks (especially when the day of the week, month, and date all change simultaneously). And the third is that, in a wristwatch, keeping the display a tasteful size while also maintaining legibility, is pretty difficult – there's more room under the dial in a pocket watch, but in a 41.5mm wristwatch that  has to stay reasonably slim, and incorporate an automatic winding system, managing space is a big challenge. One thing you'll notice immediately if you compare the pocket watch to the wristwatch is that the pocket watch has three disks for the display – one for the day of the week, one for the date, and one for the month. (Patek's archives describe month/date/day-of-the-week arrangement as "à l’Américaine" that is, in the American style.) The use of a triple-disk arrangement in the wristwatch, however, would've required either too large a disk to fit comfortably into the case and under the dial, or one in which the double-digit dates would've been illegibly small. Patek also wanted the four display disks to lie on a single plane, so as to keep the watch as flat as possible. A New Movement, In An Old-School Execution A look under the dial of the 31-260 PS QL shows the arrangement of the perpetual calendar disks, as well as the moon-phase, leap year, and day/night indication (a very useful aid to setting a perpetual calendar). As with any craft, when it's done at a high level, it looks easy and, indeed, the organization of the displays and disks seems so logical as to be almost inevitable. However, quite a lot of thoughtful, innovative engineering went into the perpetual calendar works. The cadrature/ under the dial works of the caliber 31-260 PS QL, showing the calendar disks, moon-phase disk, day/night indication (left), and Leap Year indication (right). The perpetual calendar mechanism is the subject of three patents. The first is for the "double ball bearings with coplanar balls" (and please don't fulfill my lower expectations of humanity in general by making the obvious ribald remarks in the comments, albeit I am forced to concede that, at least in idiomatic English, the jokes kind of write themselves). This system ensures that energy losses through friction are reduced to a minimum. The second patent is for an anti-shock system, which helps secure the disks in position and which also eliminates the risk of a double jump of any of the disks when switching, either during setting or when in actual use. Finally, a third patent covers the instance when the date switches from the 31st to the first. When this occurs, the ones disk (unit disk) must remain in place while the tens disk switches; Patek says "this is handled by a 31-point star from which two teeth were removed." The perpetual calendar is driven off a classic 12-step cam, in which the depth of each step corresponds to the length of each month, and which rotates once per year. There is also an equally classic four-step cam which rotates once every four years, to control the switching of the date for the month of February. The use of a full linear display adds an additional 118 parts to the movement, over a more conventional perpetual calendar design. Patek enthusiasts will find the view through the display back somewhat familiar. That's because the new movement is based on the existing 31-260 REG QA, originally launched in 2011 in the Ref. 5235 Annual Calendar Regulator . (Technically, the new movement is a modulear perpetual calendar, although it's so well done you kind of have to throw blanket condemnation of modular construction out the window). Even here, however, there are some visible and notable differences in design and execution (though, of course, the major engineering and watchmaking differences are hidden under the dials of both watches). One obvious difference is the use of platinum for the microrotor in the new linear perpetual calendar, rather than 22k gold. Patek says part of the reason for using platinum is that it's denser than gold, which makes for slightly greater efficiency (pure platinum is about 11% more dense than pure gold). Another visible difference is that the bridges in the new 31-260 PS QL have been redesigned from the annual calendar version. The inner edges of the bridges for the automatic winding system and mainspring barrel bridge are more elaborate, and there are now separate cocks for the escape wheel and balance wheel. Overall, I think the PS QL version is more satisfying aesthetically, with a stronger connection to classic Swiss full-bridge movement design. The movement also has a system for uncoupling the rotor from the automatic winding system when the mainspring is fully wound, which helps save wear and tear on the winding train. The entire perpetual calendar mechanism is jeweled throughout (again, in order to reduce friction and save energy, the movement runs in 55 jewels total), and the frequency goes up in the new caliber as well, from 3.2 Hz to 4 Hz (28,800 vph). People sometimes say that you shouldn't have a display back on a watch in which the movement doesn't give you something spectacular to look at in terms of finish. I don't necessarily agree with that – I had a ton of fun looking at the movement in my first Seiko 5, back when Dinosaurs Ruled The Earth. At the same time, however, whomever owns a 5236P is in for a real treat. Movement finishing looks to be absolutely classic Patek finissage – meticulous, thorough, and an example of unostentatious but exacting excellence in Genevan movement decoration. A Fan-Favorite Case The case design is also something that Patek fans will recognize – it's reminiscent of the design Patek used in the ref. 3448, which was Patek's first perpetual calendar and which was produced from 1962 to 1981. That watch is a major Holy Grail for Patek collectors, at least persistent and well-heeled ones, and which generates record-setting results. One in white gold hammered at Christie's for HKD 5,000,000 in 2020 (that's $643,240 at today's exchange rate) and another in yellow gold, also in 2020 and at Phillips, went for $529,200, a record . A yellow-gold 3448 sold in 2020 at Phillips. The case and dial details are pretty much exactly what you would expect and hope for in a Patek perpetual calendar, and are very much in line (hahaha...yes, I'm laughing at my own jokes) with the execution and attention to detail you find in the movement. In fact, the whole thing strikes me more and more as a bit of a rebuke to all the 5711 hype – now don't get me wrong, that's a fantastic looking watch and a meaningful piece of horological history in its own right, but the new 5236P is a stellar example of what I have always thought of as the real Patek Philippe. (In this I mean no disrespect to 5711 owners or to the watch, but the 5236P is a very tempting watch about which to use the term "masterpiece.") I feel more and more nowadays, as a watch writer, that I have to sit down and take a deep breath when I see what real haute horlogerie costs, but on the other hand, a Patek perpetual calendar has never been an inexpensive proposition. At $130,110 this is an expensive proposition, sure, but on the other hand, the much more conventional ref. 5327G in white gold is already $96,990 (admittedly, a difference of $36,000 smackeroos is nothing to sneeze at, but between the premium you expect to pay for platinum, plus the technical fireworks, the asking price for the 5236P seems high but not unreasonable). If you're a perpetual calendar fan, Watches & Wonders has been quite a lot of fun so far – we got a lovely new one from Lange , a world record for slimness from Bulgari , a wonderful openworked perpetual from Vacheron , and a modest little something from JLC, with prices running from $59,000-$89,000 for the Bulgaris, all the way up to $1.38 million for that Reverso . Seeing Patek bring out the big guns is fantastic – and the new 5236P is a watch that combines brains, beauty, and history in a uniquely Patek Philippe fashion. The Patek Philippe Ref. 5236P-001 In-Line Perpetual Calendar: Case: 950 platinum. Sapphire-crystal caseback and interchangeable solid platinum back. Water resistant to 30 m (3 bar). Diamond at six o'clock Diameter: 41.3 mm Length (across lugs): 48.61 mm Width (9 to 3 o'clock incl. crown): 44.35 mm; Overall height (crystal to lugs): 11.5 mm; Height (crystal to back): 11.07 mm Width between lugs: 20 mm Movement: Caliber 31-260 PS QL: self-winding mechanical movement. Full perpetual calendar with an in-line display of the day, date, and month. Leap-year cycle and day/night indicator. Moon-phases. Subsidiary seconds. Dimensions, 34 mm (basic caliber 31.74 mm, calendar module 34 mm) 5.8 mm (basic caliber 2.6 mm; calendar module 3.2 mm) 503 components (basic caliber 205, perpetual calendar 298). Runs in 55 jewels with a power reserve of 38-48 hours. Platinum microrotor; unidirectional winding; frequency, 28,800 vph. Price, $130,110. See more at Patek.com.Patek's latest technical tour-de-force comes in a collector-favorite case as well.