It was in 1992 that Philippe Stern, president and owner of Patek Philippe, tasked his watchmakers with creating a timepiece that would bridge the gap between simple calendar functions — date or day/date only, with adjustments necessary at the end of each month shorter than 31 days — and the mechanically elaborate and (for some) prohibitively expensive perpetual calendars, which account for the lengths of every month and even leap years, requiring adjustment only every hundred-odd years.
It wasn’t until 1996, however — 20 years ago — that the result of this horological challenge was presented to the public. Patek Philippe Ref. 5035, said to be the very first annual calendar wristwatch, with a patented construction, was voted Watch of the Year in 1997 and spawned an entirely new category of “useful complications” in the watch industry as well as 21 Patek Philippe watches over the past two decades equipped with annual calendars. The newest, Ref. 5396, a highlight piece from Patek’s collection at this year’s Baselworld, is intended as a celebration of this significant anniversary both for Patek and the watch world overall.
Like its predecessors, the new Patek Philippe Ref. 5396 requires adjustment only once per year, accommodating the lengths of all months except February. It comes in the now-iconic Patek Philippe Calatrava case, a style and shape that dates back to 1932 and has become “the archetype of all classic round watches,” according to Patek. Measuring a contemporary but relatively modest 38.5 mm in diameter and 11.2 mm thick, the case flows seamlessly into the strap lugs and frames the curved sapphire crystal with a smoothly polished bezel.
Underneath the crystal, the dial displays the classical elements of Patek Philippe’s calendar watches — an in-line double window in the upper half indicating the day and month; a large aperture at 6 o’clock for the date; and a moon-phase display ringed by a 24-hour subdial in the lower half. This layout is reminiscent of Patek’s perpetual calendar wristwatches of the 1940s and ’50s, the only aesthetic difference being the 24-hour scale, which serves as a day-night indicator, replacing the 31-day analog date scale of the vintage models.
The applied Breguet-style Arabic hour numerals are in 18k gold, with gold dots indicating the minutes. The Dauphine hour and minute hands have sharp center ridges and polished bevel flanks that taper into the tips. A long, slender hand counts the sweep seconds, while a small, gold, leaf-shaped hand tracks the time on the 24-hour day/night subdial.
All these functions are powered by Caliber 324 S QA LU 24H, an automatic movement that the wearer can admire through the watch’s clear sapphire caseback. It offers the wearer a very user-friendly experience when setting and resetting the calendar: the one yearly adjustment necessary, from February into March, takes just seconds thanks to the inset corrector buttons in the side of the case. The moon-phase requires even less regular attention; thanks to its precise-reduction wheel train, it should only need adjustment by one day every 122 years.
As is typical of Patek Philippe movements, Caliber 324 S QA LU 24H is meticulously decorated in classical haute horlogerie fashion: rhodiumed bridges with côtes de Genève; round-chamfered edges and gold-filled engravings; an engraved Calatrava cross on the big, 21k gold rotor, along with circular graining and perlage; snailed patterns on the beveled flanks; and red bearing jewels. The movement also strives for superior rate accuracy, incorporating Patek’s proprietary Gyromax balance with a spring made of Silinvar, a derivative of silicon. It beats at a frequency of 28,800 vph and stores a maximum 45 hours of power reserve. Like every Patek Philippe caliber since 2009, it has met the stringent standards of the company’s in-house quality mark, which exceed those for COSC chronometer certification.
The Patek Philippe Ref. 5396 Annual Calendar is available in two distinctive executions, both priced at $47,970 — one with a 5N rose gold case and silvery white opaline dial, the other in an 18k white gold case with a galvanic gray, sunburst-finish dial. The former comes on a chocolate brown alligator strap with rose-gold Calatrava fold-over clasp, while the latter is on a large-scaled matte black alligator strap with a white gold clasp.