Patek Philippe introduced a new function for calendar watches at Baselworld 2019. The weekly calendar is a semi-integrated mechanism that in addition to the day of the week and the date also displays the week number. Further, the Calatrava Weekly Calendar is endowed with a totally new self-winding base caliber; it is also the only steel Calatrava in the current Patek Philippe collection.
Patek Philippe has developed a broad spectrum of calendar functions, from the simple aperture date to the extremely complex secular perpetual calendar that is preprogrammed into the 28th century. For quite some time, the perpetual calendar has established itself as a genuine specialty of the manufacture.
The patented Annual Calendar, launched in 1996, triggered a small revolution as a full calendar that only needs to be corrected once a year on March 1. In 2013, the Ref. 5200 Gondolo “8 Days, Day & Date Indication” was welcomed as a fascinating innovation with its instantaneous day-of-week and date display. Now, Patek Philippe is taking a step forward by expanding its collection of “useful complications” with the addition of a weekly calendar that displays the current week number. It is a decidedly practical function for business people in a globalized world.
The Calatrava Weekly Calendar expresses its uniqueness with a silvery opaline dial and the unusual layout with five hands from the center – quite a rare configuration. The hours and minutes are indicated with elegant Dauphine hands in blackened white gold. They feature two lapped facets, a perfect match for the applied baton indexes in blackened white gold with four lapped facets each.
A slender counterbalanced hand tracks the seconds. The day of the week is displayed by a hammer-shaped hand with a red hammer head on a circular scale in the middle of the dial. A second hand of the same design delivers week number and month readings on two concentric scales at the periphery of the dial. These calendar indications are complemented by an aperture date at 3 o’clock.
Another special feature: The typography created explicitly for this watch is based on the handwriting of one of the manufacture’s designers; its letters and numbers are absolutely unique. Carefully printed in black, they add very personal and poetic notes to the dial of the Ref. 5212, recalling an epoch in the not too distant past when notes were still written by hand in paper diaries.
With a diameter of 40 mm and a thickness of 11.18 mm, the stainless steel Calatrava case – a rarity at Patek Philippe – also stands out on account of the finesse of the bezel that extends over the two-tiered, gently curved strap lugs. The case is cold-formed in the manufacture’s ateliers with high-tonnage presses and then meticulously hand-polished by experienced artisans – a highly complex undertaking given the many sharp edges and angles.
Its aesthetic appeal is inspired by a one-of-a-kind piece made in 1955 and held in safekeeping by the Patek Philippe Museum; in 2012, at a Sotheby’s auction, it fetched a record price of 962,000 dollars. This kinship is emphasized by the reference number of the new Calatrava Weekly Calendar that consists of the same numerals in a different order. The vintage aspect is amplified by a box-type sapphire-crystal glass with a slightly cambered profile. The stainless steel snap back has a sapphire-crystal inset that allows the movement to be observed at work.
The manufacture places great emphasis on convenience and user-friendliness. Pursuant to the international ISO 8610 standard, Patek Philippe chose Monday as the first day of the week rather than Sunday, which is commonplace in some countries. The first week of the year is the week that includes the 4th of January. The 53-graduation scale considers years with an extra week. This is the case every 5 to 6 years. The next occurrence falls in 2020.
The weekly calendar mechanism is not the only special feature of the Ref. 5212. Patek Philippe also endowed this watch model with a totally new movement based on the self-winding caliber 324. It is the outcome of several years of development work. The caliber designation reflects its diameter of 26.6 mm and height of 3.3 mm.
The new movement sports several innovations and optimizations that improve its performance and dependability. The first innovation concerns the fourth-wheel pinion. To prevent the seconds hand from vibrating and to reduce friction, the manufacture’s engineers decided against the habitual third wheel with a friction spring to eliminate the need for precision adjustments. They replaced it with an innovative system based on an anti-backlash wheel. This patented component is made of a nickel-phosphorous alloy with the LIGA process (lithography, electroplating, molding) and then completed with a gold-copper-iridium coating.
It features an avant-garde geometry with long bent teeth, each with a tiny integrated 22-micron leaf spring that engages with the leaves of the fourth-wheel pinion to suppress vibrations of the seconds hand without any prior adjustment work. Friction is further reduced by suspending the pivots of the seconds-hand arbor between bearing jewels. The stop seconds (balance stop) mechanism provides further optimization: it becomes effective when the crown is pulled into the hand-setting position. Thanks to this device, the user can set the time with one-second accuracy. When the crown is pushed home, the mechanism kick-starts the balance, so to speak, to set it in motion again.
Further substantial modifications improved the efficiency and longevity of the unidirectional winding mechanism. The first optimization of the automatic winder with the centrifugal mass replaces the traditional uncoupling yoke with a pinned spring by introducing a new patented clutch wheel that is manufactured with a highly complex process. It drives the mainspring barrel in one direction and uncouples it in the other direction. The second optimization consists of a reduction wheel that is uncoupled from the automatic winder when the watch is manually wound.
When parts that generate friction and need to be tweaked are replaced with high-tech components, this improves the performance and dependability of the movement. With its 304 parts (including those for the weekly calendar mechanism), the all-new caliber 26-330 S C J SE is a perfect manifestation of Patek Philippe’s tradition of innovation. The sapphire-crystal case back of the new Ref. 5212A-001 Calatrava Weekly Calendar reveals the refined architecture and painstaking finissage of the movement as prescribed by the Patek Philippe Seal.