Weekly planning is one of the greatest tools for those with long-term projects in the pipeline, allowing the tracking of tasks and deadlines over the duration of a whole year. What better way to help keep a project on track than with a weekly calendar complication in the form of the elegant Calatrava Weekly Calendar Ref. 5212A-001 by Patek Philippe?

This new timepiece joins a long list of calendar timepieces by Patek Philippe, from the brand’s simple aperture date timepieces to the most complex perpetual calendars that, if kept wound, won’t need to be set until the 28th century! Patek Philippe has carved out a place for itself as one of the leaders in perpetual calendars and this Calatrava Weekly Calendar is a useful complication that will surely appeal to a wide range of watch lovers.

The Working Week

The first day of the week varies according to different countries and cultures around the world. Some countries start the week on a Friday, while others begin on a Saturday or a Sunday. To avoid confusion, Patek Philippe’s Calatrava Weekly Calendar starts each week on a Monday, in accordance with ISO 8601, the international standard for date- and time-related data that first came into effect in 1988.

The start of the week isn’t the only aspect of our weekly schedules that can differ — when it comes to the number of weeks in the year, there are not always 52; every five or six years there are actually 53, with the next 53-week year occurring in 2020. This is because 365 or 366 days is not neatly divisible by seven days, making the art of displaying the weeks on a timepiece more complicated that it may first appear.

A Handwritten Aesthetic

The Patek Philippe Calatrava Weekly Calendar displays the current week number around the periphery of the dial, in a ring just under another scale with the months of the year, both of which are indicated using the same red hammer-shaped hand. The letters and numbers are elegantly positioned in a charming, legible, hand-written font that is the actual handwriting of one of the brand’s designers. This use of handwriting recalls an epoch in the not-so-distant past when notes were still written by hand in paper diaries, giving the watch a slightly vintage feel.

The dial features a handwritten font which is actually one of Patek Philippe’s designer’s own handwriting
The dial features a handwritten font which is actually one of Patek Philippe’s designer’s own handwriting

The timepiece shows the date in an aperture at three o’clock and the days of the week in a circle around the middle of the dial, which are also indicated by a red hammer-shaped hand. Even though there is a lot of information on the dial, the aesthetic is clear and elegant, thanks to five superimposed hands in the center. This is quite a rare configuration due to it being quite difficult to achieve. Other details worthy of a closer look are the silvery opaline dial, the blackened gold applied hour markers and the Dauphine hands with their two facets, making the dial extremely attractive to the eye.

The timepiece comes in a stainless steel Calatrava case whose design was inspired by a historic Calatrava timepiece from 1955, the Ref. 2512, which was rather large for the time at 46mm. For those who love small details, the new reference number uses the same numbers as this historic piece, just in a different order.

This new model is smaller at 40mm with a thickness of 11.18mm, but features the same three-piece construction and two-tiered lugs that gracefully flow over the case band. The case is cold-formed in the Patek Philippe workshops using high-tonnage presses. It is then meticulously hand-polished by experienced artisans, which is highly complex due to the many sharp edges and angles.

Patek Philippe Ref. 5212A-001 Calatrava Weekly Calendar

The history of the Calatrava collection dates back to 1932 and its design is as timeless and understated today as it was back then. The Calatrava cross was the emblem of The Calatrava Order, a Spanish knighthood founded in the 17th century. Their coat of arms evokes the values of the knights — perseverance, bravery, courage and independence — character traits that are also important for Patek Philippe. There have been more than 20 different versions over the years, starting with the first, the Ref. 96, that was influenced by the Bauhaus art movement that followed the philosophy that form should follow function. This new version continues this philosophy with its pure and simple design.

The Week Module

The new semi-integrated module is in charge of displaying the day of the week and the number of the week. It contains 92 parts and is particularly svelte at a height of 1.52mm. A seven-point star on the hour wheel in the center of the movement controls the day of the week, while a lever and a second seven-point star with an extended Sunday tip drives the 53-tooth week wheel.

A Brand-new Self-winding Caliber

The Calatrava Weekly Calendar is equipped with a totally new self-winding, performance-optimized base caliber — the new Caliber 26-330 S C J SE — that has a 45-hour power reserve. This new family of movements is an important evolution of the brand’s Caliber 324 with improved reliability. It will be totally interchangeable with the Caliber 324 moving forward.

The history of this movement dates back to 1982 with the Caliber 310/335 that beat at four hertz. In 1991, the brand dropped to three hertz with the Caliber 315-330 and returned to four hertz in 2004 with additional changes to hand-setting and automatic winding. This year marks the most reliable movement to date with the Caliber 26-330.

For those who love the mechanics, there are a number of improvements that have been made to this movement in comparison to its predecessor. Firstly, the manufacture’s watchmakers decided against the habitual center-second pinion with friction spring. Instead, they have favored an innovative system based on an anti-backlash third wheel. The advantage of this new system is that it prevents the seconds hand from vibrating, and eliminates friction. This patented component is made from a nickel-phosphorus alloy using LIGA technology (a German acronym for lithography, electroplating and molding), which is then coated with a gold-copper-iridium treatment. It features an avant-garde geometry with long split slotted teeth, each with a tiny integrated 22-micron leaf spring that engages with the second pinion teeth to suppress vibrations of the second hand without any prior adjustment work.

Patek Philippe Ref. 5212A-001 Calatrava Weekly Calendar

Friction has also been further reduced by suspending the pivots of the seconds-hand arbor between bearing jewels. The stop seconds’ mechanism provides further optimization as it becomes effective when the crown is pulled out into the hand-setting position. Thanks to this improvement, the user can set the time with an accuracy within one second.

The self-winding mechanism also sees a number of improvements. Firstly, a new automatic winder with a centrifugal mass replaces the traditional uncoupling yoke complex process. It drives the mainspring barrel in one direction and uncouples it in the other direction. And secondly, further optimization has been achieved thanks to a reduction wheel that is disengaged from the automatic winder when the watch is wound.

In total, there are four patents for this new semi-integrated mechanism, two for the base movement and two for the additional module.

The Patek Philippe Calatrava Weekly Calendar may be complex on the inside, but it is extremely easy to use thanks to a three-position crown (position one is for winding the watch, position two for setting the date, and position three for setting the time). The week number is set via a corrector at 10 o’clock and the days of the week can be modified via a corrector at eight o’clock. The beauty of the mechanism is that the user can make changes at any time of day or night, which is certainly not the case for all calendar complications.

The timepiece is fitted with an elegant, light-brown, calf-skin strap; it has a box sapphire crystal, which reinforces the vintage touch and it comes with a sapphire crystal caseback for curious eyes. The watch is also water-resistant to 30 meters and comes at a price of CHF 29,500.

Patek Philippe Ref. 5212A-001 Calatrava Weekly Calendar (Image © Revolution)
Patek Philippe Ref. 5212A-001 Calatrava Weekly Calendar (Image © Revolution)

The timepiece took several years of development to produce, which meant the constructors, watchmakers and designers at Patek Philippe know all about weekly planning. They may well have created this brand-new complication for themselves first, and who would blame them, it is just gorgeous!