The Patek Philippe Reference 5235/50R-001 annual calendar with regulator-style display was my favorite watch of Baselworld 2019.

First I’ll briefly touch on its background before describing its defining characteristics and outlining its significance. Let’s begin by taking a look at what its place in the brand’s collection is.

Patek Philippe Reference 5235/50R: place in collection

This is the first update of the Patek Philippe 5235 since its original release in June 2011. In those eight years, collectors who have learned to appreciate its subtle refinements and cool aesthetic appeal have been part of a community so small and so new, they don’t even have a secret handshake yet.

Reference 5235/50R receives a pink gold case for 2019 in addition to a dial rendered in tone-in-tone graphite and ebony hues, white lacquered hands, and “phantom branding” revealed in the right light at the right angle. The watch comes on a matte black, square-scaled alligator strap featuring a beautifully decadent pink gold buckle with a trapezoidal “Patek Philippe” signature.

The inspiration for Reference 5235/50R-001 comes from regulator pendulum clocks originating in the late seventeenth century. These were precise reference timers designed to be highly legible, especially the seconds as watchmakers would use their regulator clocks to set and adjust other timepieces. Reference 5235 is Patek Philippe’s tribute to those clocks.

Patek Philippe’s first regulator-style wristwatch from 2011 was however specifically inspired by a clock hanging in previous brand president Philippe Stern’s office. His son, Thierry Stern, took over in 2009.

Electronic timekeeping has since replaced mechanical reference regulators; however when they were still in use, the hour display on the mechanical clocks was deemed of secondary importance. What mattered most was setting time to the second, so a central seconds indication was the main display, the hour hand placed in a subdial so as not to obscure the seconds.

The regulator was also deemed essential in marine applications. Every time a ship returned to port, its chronometer would be adjusted using a regulator.

When Reference 5235G – now discontinued with the arrival of the pink gold version – was introduced in 2011, it was encased in white gold and featured a tone-in-tone silver and white dial. The blue hands and dial printing, along with a navy blue leather strap, were a nod to these regulators and their maritime associations.

The significance of Patek Philippe Reference 5235/50R’s Caliber 31-260 REG QA

In developing the movement for Reference 5235, Patek Philippe decided against using its ultra-thin Caliber 240 as a base. Instead, the brand created an entirely new movement: Caliber 31-260 REG QA with 313 parts.

The automatic movement, only 5.08 mm high, is wound by a 22-karat gold micro rotor and beats at a quirky 3.2 Hz (23,040 vph).

As an annual calendar, the watch automatically adjusts for months with 30 and 31 days, requiring only a single correction once a year at the end of February.

As Martin Green pointed out in Annual Calendars Are Goldilocks Complications: Not Too Hot, Not Too Cold, Just Right, the annual calendar is a relatively recent invention by Patek Philippe, with the first wristwatch ever featuring the new complication being the brand’s Reference 5035 in 1996. Over the years the annual calendar has become an essential part of Patek Philippe’s collection, benefiting from continual technical and aesthetic refinements – and Caliber 31-260 REG QA is one of the movements to profit.

This movement is proprietary to Reference 5235 and features Patek Philippe’s own Pulsomax escapement and Spiromax balance spring in Silinvar, rendering it highly resistant to magnetic fields. The development of these technical innovations was the fruit of the Patek Philippe Advanced Research department’s labor (see more about that in Give Me Five! All 5 Of Patek Philippe’s Advanced Research Limited Editions).

Coming in at a svelte 10 mm in height and 40.5 mm in diameter, the updated pink gold case trades calm aplomb for commanding gravitas.

Patek Philippe Reference 5235/50R’s case

Unlike the novel regulator-style display, this watch’s case shape and lugs have historical precedence in the back catalog of Patek Philippe wristwatches. References 3448 and 3450, for example, are rare perpetual calendar watches combining annular bezels with angular lugs, masterfully juxtaposing volumes of round curves and straight lines with panache and proportional elegance.

The lugs of Reference 5235 develop from the case band with a dart-like conviction. They reduce in volume, retaining their linear form, before terminating in a sheer descent, a tight radius cropping their flanking edges. Trapezoidal from every angle, they have a rounded underside for comfort on the wrist.

The lugs are polished on every side but one, where the horizontal graining of the case band extends to appear as an unbroken surface finish along the lateral profile of the lugs. The lugs on Reference 5235/50R have extra height compared to the previous reference.

The lugs also feature a rounded lick of a bevel between the top surface and flanking edges, providing a wonderful organic and simultaneously gem-like facet of light play that adds warmth and brightness to the well-defined and crisp nature of the case, a feat repeated on the fully polished buckle.

At the confluence of case and lugs, the vertical top of the lug crests and drops back into the mid case, creating a surface that is impossible to see but is entirely delightful in its conception only revealing its form when viewed in profile. Blink and you miss it.

The congruent horizontal graining found on the case band defines the mid case. The grain is silken and delicate, analogous in its purpose with the rest of the case, which is all high polish. The case band is slim, featuring prominent bevels on either side further punctuating its lean stance within the case. This is very evocative of vintage and classical dress wristwatches and is, perhaps, the most visually assertive statement of its aspirations in the entire case assembly.

The high-polished bevel above the case band is short and steep, giving seat to a suitably mirrored bevel on the end of the bezel. The bezel, also in high polish, is reasonably broad and flat, sloped to make full use of the negative spaces created by the bevels below.

Although narrow relative to the case diameter and dial real estate, the bezel frames the watch with poise. Its width is measurably the same as that of the case band – a seemingly minor detail that may not otherwise be important, but one exemplifying proportionality.

With a case diameter of 40.5 mm, this annual calendar is appropriately sized given the complexity of the watch and the nature of the display. Although classically proportioned, it is not classically sized but rather offers a contemporary rendition of a vintage aesthetic otherwise only found in the glossy catalog pages of top auction houses.

The Patek Philippe Reference 5235/50R-001 is a thoroughly modern tribute donning its persona with panache. The warm tones of the pink gold case and the rich darkness of the dial help the watch pare some of its visual expanse.

Patek Philippe Reference 5235/50R’s dial

The dial is characteristically restrained in true Patek Philippe style while providing quite a lot of visual interest. The dial base itself is vertically satin finished in a graphite hue, a medium-dark shade with the slightest tinge of underlying blue observable from beneath its textured surface.

The color is very articulate, appearing dignified and composed. The Patek Philippe signature is precisely engraved at 3 o’clock. It is not color filled, stealthily awaiting the right light at the right angle to be seen. Were lasers involved? I cannot be certain, but suspect so.

The periphery of the dial is occupied by a similarly satin-grained, albeit ebony-black, ring with a white railroad-style Arabic numeral minute track featuring a slab serif neo-deco typeface achieved by transfer printing.

The hour and second subdials at 12 o’clock and 6 o’clock are surrounded by pink gold-colored rings defining their countersunk edges. The ebony-colored subdials are elaborately decorated with fine concentric snailed finish.

However, unlike the railroad minute track, the subdials lack the vertical satin finish found in the field of the dial base. The effect, therefore, is akin to ripples in pools of ink.

The subdials are transfer printed with a white railroad-style Arabic numeral hour-and-second track featuring the same aforementioned slab serif neo-deco typeface at 12 o’clock and 6 o’clock respectively.

The seconds subdial at 6 o’clock features a cutout date window whose execution is expertly done, providing a wide aperture with handsome finishing on the beveled edges. The date disk features a black background to match the black subdial with white printing in a neo-grotesque sans serif typeface.

The same can be said of the day and month windows that flank the subdial for hours. Although slightly harder to read than the date, the printing on the day and month displays is sharp, and the finishing of the windows is crisp.

Overall, an anodyne execution with one small exception: neither the subdials nor the calendar displays achieve symmetry. It is slight, but noticeable. I cannot explain why, but it is not a nit worth picking in my opinion.

The white gold handset gracing the graphite-and-ebony-colored dial is lacquered in white. The minute hand is a slender baton, as are the hour and second hands. The latter two, however, gain a counterbalance absent on the minute hand. The minute hand also features a pointed tip.

The hands are extremely well finished, and the near two-dimensionality of their form makes judging lateral surface treatment harder; there is a marked effort to not yield at simply machined output. The hand-finishing exudes delicate deftness, and it is a delight to see that effort was not spared.

The white graphic essentials of handset and printed displays contrast with the dark dial fields tremendously well, and therefore the legibility of the dial and its display remains exceedingly high.

The slim hands are, of course, true to the spirit of the regulator display. However, in wristwatch application, the form does not reduce the experience of reading the time or other information clearly and efficiently. The relationship between the thin case and hands is quite pleasant and complementary.

As I viewed the minute hand trace a graceful arc, I was reminded of the VU meters I wanted but never got in college. This is a remarkable quality to me, anyway: a watch creating nostalgia in a manner I never expected. Now I feel the urge to go to the Hi-Fi store one evening.

The qualities of the dial and the handset are generous and forgiving. It is a successful display that is artfully effectuated commanding a lingering gaze.

The crown on the 3 o’clock side of the case is a 22-toothed hand-finished affair in high polish. Of a generous diameter for this style of watch, it sits flush with the case band. The signed Calatrava cross on its domed finial is soft and subtle, a contrast to the straight and deep knurled grip.

To be fair, the knurled tips are also rounded to be soft to the touch. However, there is ample surface area for easy manipulation.

The other way to manipulate the movement is by using the three correctors set into the 9 o’clock side of the case. Used for manipulating the calendar features, these consist of deep, conical, high-polished sprung indentations that receive a countersink each, also in high polish. The contrast with the fine grain of the horizontal satin finishing along the case band is immediate and indicative of the attention to detail placed by Patek Philippe on appreciating refined execution in all components.

These, along with the snap-on case back, leave Reference 5235 water resistant only to 30 meters, or adequate to withstand a drizzle or splash of water.

The case back snaps onto a beveled plane below the case band, allowing for the slimness of the overall case. Some thickness is tolerated because of the sapphire crystal on the case back that allows a generous view of the sized-to-fit micro-rotor automatic movement.

Caliber 31-260 in detail

The movement itself, worth the price of admission, is finished unlike many of Patek Philippe’s other offerings.

Caliber 31-260 is a modern movement with an attractive construction and remains the only serially produced Patek Philippe movement with silicon hairspring and escapement. And it’s unique to the Reference 5235/50R.

Unusually for a Patek Philippe, it features stop seconds, generally referred to as hacking seconds, a feature befitting its regulator nature by stopping the balance when the crown is pulled out to set or adjust the time precisely. This was the first Patek Philippe wristwatch movement in history to include hacking seconds.

The base plate is decorated with circular graining, perlage in French, which is hand-applied and expressive of the Patek Philippe tradition.

A micro perlage pattern is found under the off-center 22-karat gold micro rotor as well as beneath the balance wheel. The free-sprung balance comprises Patek Philippe’s legendary adjustable Gyromax system, paired here with a silicon balance spring. The balance is secured to the plate by a balance cock with mirror-polished, beveled edges and Geneva striping on its horizontal surface.

The gold micro rotor, running on ceramic ball bearings for lubricant-free winding efficiency, is engraved with the Calatrava cross and embellished with a high polish deeply contrasting with the circular Geneva striping along its horizontal surface, while the edges have a polished bevel with a striped pattern.

The diminutive size of the off-center rotor allows a good view of the rest of the movement – which is the whole point of micro rotors – and the gear train is also partially visible thanks to finger-style bridges that are also finished with Patek Philippe’s Geneva striping. The mirror-polished, beveled edges of the bridges cascade gracefully over the base plate.

The bridges are also defined by their sharp and angular tips poetically reminiscent of mountaintops, a departure from the otherwise traditionally soft and rounded Patek Philippe finishing aesthetic. This is also a romantic representation in my mind of the lofty goals set and achieved by Patek Philippe watchmakers in creating Reference 5235 and its exclusive movement.

Visible jewels are set in high-polished countersinks along with chamfered and polished screws, with beveling around the screw heads finished to a high polish as well.

The gear train is finished traditionally, with each tooth of every gear seeing hand-finished touches for refinement.

The overall quality of decoration and finishing of the movement is extremely high, and coupled with the technology and pedigree it makes this a truly remarkable movement of exceptional capability in terms of timekeeping efficiency, uniqueness of character, and competitive value.

There simply is no other Patek Philippe like Reference 5235, and there is no other movement like Caliber 31-260.

Patek Philippe Reference 5235/50R’s strap and buckle

The hand-stitched, matte black alligator leather strap is the perfect accompaniment to the black dial and features Patek Philippe’s easily removable spring bar system.

The spade pin buckle adorning the closure end of the strap is pink gold, finished to a mirror polish, with a scrolling “Patek Philippe” signature that is also unique to this reference. The relief features a fine, grained texture serving as a backdrop from which the highly three-dimensional rounded forms of the brand’s name rise with conviction. It is a fantastical detail well deserving of mention.

Conclusion: if you haven’t already guessed, I like it!

Patek Philippe Reference 5235/50R-001 is full of myriad details, each one issuing delight.

This variation on an existing theme is beautifully executed, but lacking some of the excitement of a brand-new timepiece. That makes this watch paradoxical because it is a variation of a reference that has called the Patek Philippe catalog its home for the past eight years: to me it is still so new, so novel, so unlike what Patek Philippe has been doing in the past, that even an update to case material and dial color merits all the excitement of a brand-new release.

The new pink gold case now emanates a radiant and powerful statement in distinction over the cool white gold. The eloquence of the black dial begs attention and veneration. It has earned its place in the collection as one of the most definitive watches of the modern Patek Philippe era with excellence, remaining one of the rarest and most imaginative expressions of the brand.

And all this makes Reference 5235-50R my favorite watch from Baselworld 2019.

A lot has been written about the need for more interesting and novel watchmaking from independently owned high-horology brands. I propose that it already exists and has just been updated to its most stylistic version yet. It just so happens to come from Patek Philippe, demonstrating this brand’s true capability when it is at the top of its game.

If independently owned high horology with a flair for the artistic and more than a hint of the technical, blending tradition with modernity, is the firewood that burns your passion for watches, then I highly recommend the Patek Philippe Reference 5235/50R annual calendar with regulator-style display.

You might just find it’s worth your hard-earned money.

For more information, please visit www.patek.com/en/collection/complications/5235-50R-001.

Quick Facts Patek Philippe Reference 5235/50R-001
Case: 40.5 x 10 mm, pink gold
Movement: automatic Caliber 31-260 REG QA with Pulsomax escapement and Spiromax balance spring in Silinvar, micro rotor, 31 jewels, 48-hour power reserve, 3.2 Hz/23,040 vph frequency, Patek Philippe seal
Functions: hours, minutes, hacking seconds; annual calendar with day, date, and month
Price: $51,825/€46,630

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