The Patek Philippe Ref. 5320G Perpetual Calendar bears the vintage influence of several historical predecessors, including that groundbreaking 1925 model — a unique piece dubbed 97’975, and currently part of the collection at the Patek Philippe Museum in Geneva — as well as several other perpetual calendar watches from the 1940s and 1950s, most of which make only rare appearances nowadays, usually on the auction block. Patek first integrated the perpetual calendar wristwatch into its regular collection in 1941 with the introduction of Ref. 1518, a watch that combined a perpetual calendar with a chronograph. A year later, Ref. 1526, a model without a chronograph function, debuted. Both pieces pioneered the distinctive dial design that still today defines Patek Philippe’s perpetual calendar timepieces: a double aperture directly below 12 o’clock for the day and month displays, and a subdial at 6 o’clock with a moon-phase indicator surrounded by an analog date display. This watch, with its historical-looking cream-colored lacquer dial, adds a few new, subtle elements to this classical layout: a small, round day-night aperture between 7 and 8 o’clock and a round aperture for the leap-year cycle, with Arabic numerals from 1 to 4, between 4 and 5 o’clock. Other familiar elements include the applied gold Arabic numerals and five-minute cabochons with luminous coating, fine-tipped baton hands filled with Super-LumiNova (a callback to Patek’s Ref. 1463 chronograph from the 1950s), a thin, counterbalanced sweep seconds hand; and the graduated seconds scale around the dial’s perimeter.
The watch’s manufacture movement is Caliber 324 S Q (“S” for seconds, “Q” for quantième perpétuel, or perpetual calendar), based on Patek’s self-winding Caliber 324, which is powered by a large rotor in 21K gold. On the dial side are four disks for the perpetual calendar displays, each rotating at its own rate inside its dial aperture: the day disk, at one revolution per week; month disk, at one revolution per year; leap year disk, at one full cycle over eight years; and the day/night disk, at one rotation per day. The moon-phase disk, behind the analog date at 6 o’clock, requires only one single-day correction every 122 years — which corresponds to a miniscule daily error of 0.02 per mil. The other side of the movement boasts the array of haute horlogerie finishes and technical refinements for which Patek Philippe has become renowned: bridges with round-chamfered and polished edges; Geneva striping; gold-filled engravings, screws with polished, chamfered slots in bores with polished countersinks; a Gyromax balance with Spiromax balance spring made of high-tech Silinvar; and the aforementioned solid-gold rotor, suspended between ball bearings and decorated with perlage, circular graining, and an engraved Calatrava cross. Like all modern Patek Philippe calibers, this one meets the strict precision and quality criteria of the Patek Philippe seal, meaning, among other things, that its maximum rate deviation ranges between -3 and +2 seconds per day.
The case, made of 18K white-gold, measures 40 mm in diameter and 11.44 mm thick. Like the movement, which is visible through a sapphire caseback, it is crafted entirely in-house, from design to final polishing. Its vintage-influenced design architecture includes so-called “box-form” sapphire crystal over the dial, which enabled the watchmakers to keep the case flanks slender. Visibly extending across the bezel, this crystal is dramatically curved, with parallel inner and outer sides, in order to prevent visual distortion of the dial regardless of the viewing angle. (Of course, such a crystal would’ve been impossible to execute in sapphire back in the 1940s and 1950s, so this watch’s historical predecessors used scratch-resistant plexiglas instead.)
Further demonstrating Patek’s attention to detail, and adherence to this watch’s heritage, even the design of the lugs comes from a 60-year-old predecessor. The Patek Philippe Ref. 2405 introduced the prominent, three-tiered, lug profile revived in the Ref. 5320G, which — in combination with the flat case middle, the beveled, polished bezel, and the overarching, curved crystal — makes for an elegant silhouette on the wrist. Also, a bonus for those who prefer an even more vintage-appropriate style: the watch comes with a solid white-gold caseback that can be swapped with the sapphire exhibition back.
The Patek Philippe Ref. 5320G Perpetual Calendar comes on a lined, hand-stitched, chocolate brown alligator strap with large square scales. It fastens with an 18K white gold foldover clasp in the shape of Patek’s iconic Calatrava cross. Its price in the U.S. will be approximately $82,800.