Patek Philippe: Calatrava 8 Days Ref.5328G

Patek Philippe presents the new Calatrava 5328G-001 featuring instantaneous day and date displays at 6 o’clock, an eight-day power reserve indicated at 12 o’clock, and an innovative manual-winding movement. The product of five years’ development, caliber 31-505 8J PS IRM CI J takes up the base architecture of the rectangular caliber 28-20 REC 8J PS IRM C J launched in 2013 in the Gondolo 8 Days, Day & Date Indication Reference 5200, but with a round shape designed to fit perfectly into a Calatrava-style case. This movement also presents several technical optimizations and innovations, particularly related to energy management and the instantaneous jumps of the day and the date. It was also designed to ensure autonomy of eight full days, with a ninth reserve day flagged in red on the arched indicator at 12 o’clock.

THE PULSOMAX ESCAPEMENT

The new caliber 31-505 8J PS IRM CI J stands out fot its exclusive Pulsomax escapement with an escape wheel and lever made of Silinvar, a silicon derivative with unrivaled physical and mechanical qualities such as lightness, hardness, resistance to magnetism, etc. Developed as part of the “Patek Philippe Advanced Research” program, the Pulsomax® escapement is distinguished by its superior performance, achieved in particular thanks to the unique geometry of the escape wheel and lever and the machining precision provided by the DRIE process (Deep Reactive Ion Etching). Its optimized performances and long-term reliability, combined with those of the Spiromax® balance spring in Silinvar®(another “Patek Philippe Advanced Research” development) are valuable assets in guaranteeing a large power reserve of eight days. 

This watch’s large power reserve is ensured by two barrels series coupled barrel allowing enough energy to be stored for the movement to function precisely for eight full days, with a 9th reserve day. The first barrel is fitted with a slip spring. When the user winds the movement, the two barrels charge simultaneously. As the main barrel discharges, the auxiliary barrel transmits its energy to it, recharging it, according to the principle of communicating vessels. 

ISTANTANEOUS DAY AND DATE JUMPS

For the instant-jump day and date mechanism, Patek Philippe returned to the principle introduced in the Cubitus Instantaneous Grand Date, Day and Moon Phases Reference 5822P-001, unveiled in October 2024 (self-winding caliber 240 PS CI J LU) –with a 24-hour wheel comprising a cam fitted with a dual- function spring. This system makes it possible to overcome a higher torque, while guaranteeing precise jumps. Each night, at midnight, the large lever equipped with two beaks falls on the 24-hour cam, and in falling, engages direct with the day star and the date star. The two indications then jump simultaneously and instantaneously, thanks to the energy accumulated throughout the day.

The day display is performed by a disk that was lightened and pierced to reduce its weight and its inertia at the moment of the jump – and thereby avoid any undesirable double jump. The date is indicated by a hand positioned on a counter concentric with the small seconds at 6 o’clock. Thanks to the beveled shape of the dual-function spring, the new caliber makes it possible to set the time at any hour of the day or night, backwards or forwards, even during the passage of midnight, with no risk of damaging the movement. Furthermore, the caliber is equipped with a “stop-seconds” function enabling the time to be set to the nearest second. The date requires correction five times a year, on the first day of the months of March, May, June, October and December, using the corrector positioned on the caseband between 3 o’clock and 4 o’clock. 

NEW DIAL AND EMBLEMMATIC CASE

In addition to its special functions and increased autonomy, the new Calatrava 8 Days stands out by its originality as regards the displays. The power reserve indication, transfer printed along an arc (is visible on a subdial at 12 o’clock, while the day aperture, the date hand and the subsidiary seconds dial form a group at 6 o’clock. This arrangement along a vertical axis, particularly legible, also endows the watch with a unique personality. The textured dial in blue with a black gradient rim presents syringe-style applied numerals and hour and minute hands, all in white gold, emphasized by a white luminescent coating. 

The caseband of the 41mm round case in white gold is decorated with guilloché work in the Clous de Paris or hobnail pattern. This emblematic decoration first entered the Calatrava collection on the bezel of Reference 96D in 1934 and returned to the spotlight in 1985 on the famous Reference 3919, one of the most beautiful symbols of the Patek Philippe style, which remained in production for more than 20 years. A refined detail, the new 5328G-001 features an unusual case construction with the lugs attached to the back, enabling the Clous de Paris decoration to wrap elegantly around the entire caseband. A sapphire-crystal case back affords a private view of the architecture of the new manually wound caliber.

The new Calatrava 8 Days Reference 5328G-001 is delivered with two straps, one in blue calfskin leather with a textile pattern and cream stitching (originally fitted), the other in grained taupe calfskin leather (additional strap). It is equipped with a new patented triple-blade fold-over clasp that improves safety and comfort and facilitates the interchangeability of the straps by allowing this change to be carried out quickly and easily, without tools. (Price €. 71,280)