Patek Philippe Calatrava Weekly Calendar Ref. 5212A: Patek’s First Production Steel Dress Watch in Decades

I really like stainless steel. I even wrote about why I think stainless steel is the most precious of metals.

Stainless steel is one of the most versatile and functional metals in watchmaking, and a large percentage of watch cases and other components are made of it. But that doesn’t hold true across the entire industry, specifically in the upper echelon of watchmaking where precious metals reign supreme.

Stainless steel has an image problem; it just seems too pedestrian. When people spend upwards of $20,000 on a timepiece, they want to know that it is exclusive and of the utmost quality.

This often leads to the inclusion of precious metals, diamonds and gemstones, and extravagant métiers d’art techniques applied in a variety of ways. Sometimes we also find ceramic and titanium because they are considered more exotic and high-tech. Some brands use expensive cases as a point of pride, claiming that its watches will only ever be made in precious metals like gold and platinum.

This creates a side effect for those brands: the precious-metal watches are considered “normal” while the unlikely and often rare moments when a watch is released in stainless steel creates a buzz of excitement and a collectors’ rush to get their hands on the coveted, elusive steel edition.

Some brands house sporty models in stainless steel, but never dress watches – usually because it seems too mundane. In the extremely rare occasions when a prototype slips out or a one-off piece is made in steel (as in the case of the A. Lange & Söhne 1815 Homage To Walter Lange), it becomes a unicorn, a legend from the start.

Patek Philippe Calatrava Weekly Reference 5212A

The most recent steel surprise comes from Patek Philippe, which at Baselworld 2019 released a new dress watch in stainless steel for the first time since the 1970s. The 5212A Calatrava Weekly Calendar is a mix of modern technology, classic style, and a couple of unique touches that help it stand out from Patek Philippe’s typical offerings, making it one of my favorite watches from this brand in a while.

Patek Philippe 5212A: “A” stands for “acier”

The magic A at the end of the reference number stands for acier, the French word for steel, which rarely shows up on a dress watch by Patek Philippe (and if it does, it is usually for a limited edition).

With the new 5212A, Patek Philippe is reaching out to a very specific segment of the brand’s base that is always calling for steel options outside of the Nautilus and Aquanaut lines. Fans are usually appeased every so often with a small limited edition, but with the 5212A Calatrava Weekly Calendar you get a complicated dress watch underneath the steely exterior.

The piece is based around the brand-new Caliber 26 330 S C J SE, a reworked and updated sibling to Caliber 324 featuring an additional 92 components for a new semi-integrated weekly calendar feature.

The Calatrava Weekly Calendar displays the date, day, and week with a passive month indication tied to the week display. The weekly calendar is separated into 53 weeks around the periphery of the dial, allowing for the eventuality of the 52 standard weeks spilling over into 53 weeks (according to ISO 8601) every five or six years (on years not divisible by seven) depending on what day of the week January 1 falls on.

Patek Philippe Calatrava Weekly Reference 5212A

The day, week, and month display is rather specific and has a few nice touches some might find unusual on a Patek Philippe timepiece.

First, the displays are all coaxial from the center (minus the date window, though the date disk is technically concentric) with five hands/pointers emanating from the center of the dial. This provided one of the bigger technical challenges when adding the weekly calendar function to the movement design, and as the only week-displaying calendar in the collection has no parallel within the brand’s collection.

Second, besides the “Patek Philippe Geneve” logo and the words “Swiss Made” at the bottom of the dial, all of the numerals, months, date, and days of the week are in an atypical handwritten type font, apparently copied from a designer at Patek Philippe known for very neat handwriting.

Dial details of the Patek Philippe Calatrava Weekly Reference 5212A

Going further, the typography didn’t just copy one version of each letter or numeral, but instead it appears that every single instance is slightly different and unique as if the entire dial was truly handwritten.

The details extend to the elongated hook of the 1s and crossbar on the 7s (the typical depiction of the numeral 7 in Europe), which add the human touch and turn the 5212A into something that feels utterly personal while remaining very technical.

It is something akin to a vintage instrument, one finished by hand as a proof of concept. Given that every Patek Philippe is so carefully considered and precisely executed, the loose style of this dial is kind of fun.

Lug detail of the Patek Philippe Calatrava Weekly Reference 5212A

The case style is a definite throwback to the Calatrava Reference 2512 from 1955, which was an oversized 46 mm unique piece featuring the same uncommon stepped lugs extending over the central case band to meet the bezel.



Updates and advances

The new 5212A takes the shape and reduces it to a more ideal 40 mm. Interestingly, unlike most pieces from other brands, the 5212A (along with a variety of other models from Patek Philippe) features a snap-on case back rather than a more common screw-down or threaded case back.

This is a very classic design that many have gotten away from, especially for higher end pieces, even though it can be a very secure case closure method.

This keeps the case to a very minimal three main pieces, a clean and simple construction that avoids the pitfalls of many modern designs that end up utilizing sometimes dozens of parts. The 5212A does have two corrector pushers on the left side of the case for the calendar, but otherwise the cold-forged case is reminiscent of the basic cases from the mid-twentieth century.

Despite its vintage appearance, the movement on the inside is anything but.

Caliber 26 330 S C J SE is completely new (though based on Caliber 324) and has used a healthy dose of know-how and technology to increase functionality and reliability of the movement.

Automatic movement visible through the display back of the Patek Philippe Calatrava Weekly Reference 5212A

The automatic winding mechanism has been overhauled, starting from a more secure nut holding the rotor instead of a simple screw; a spiral spring on the click wheel for smooth and adjustment-free ratcheting; the addition of an uncoupling reduction wheel with integrated clutch for the ability to manually wind the barrel; and a similar uncoupling wheel with a unidirectional clutch.

There is a patent pending for the uncoupling clutches as well as patents for a few features in the weekly calendar mechanism.

Movement details of the Patek Philippe Calatrava Weekly Reference 5212A

The 24-hour day-of-the week mechanism features a unique sprung advancing finger, and the jumping week mechanism is driven by two seven-finger star wheels with an extra-long finger on the second wheel.

It’s a very clever mechanism that provides a lot of movement with very simple systems that work together smoothly. Sometimes mechanisms can be overly complicated, but these show a dedication to keeping complexity as minimal as possible.

Other improvements continue with the main gear train. In earlier calibers the second hand used a friction spring to prevent chatter in the pinion, but this caused a loss of energy and reduced balance inertia.

This has been solved by replacing the third wheel with an anti-backlash wheel with delicately split sprung teeth. The wheel is gold-plated nickel phosphorous produced using LIGA micro-fabrication as the spring blade for each tooth is only 0.02 mm thick, much too small for any other fabrication process.

A stop-seconds (hacking) lever has been added as well and is the same design that has been implemented in many other calibers in recent years. The delicate lever presses against the smooth outer surface of the balance, stopping it in its tracks to allow precise time setting, but also allowing the balance to continue on with its momentum upon release because it stops it mid-oscillation.

All of these improvements, along with the Patek Philippe quality, make for an extremely reliable and rock-solid automatic movement.

Close look at the dial and hands of the Patek Philippe Calatrava Weekly Reference 5212A

When you combine the engineering inside and the more playful, vintage-inspired design on the outside, you have the recipe for a memorable watch. Then, when you add a stainless steel case – a rarity for Patek Philippe to begin with – you are left with a serious contender for one of the best calendar watches of the year.



As someone regularly focusing on the avant-garde, ultra-modern, sci-fi-like pieces of the watch world, this 5212A Calatrava Weekly Calendar surprised the heck out of me.

Patek Philippe Calatrava Weekly Reference 5212A

Sort of like with Rolex, I am never expecting too much outside the norm from Patek Philippe: the brand always delivers a very well-polished yet relatively sober collection that I find very, very nice, yet often falls just short of breathtaking.

I get really excited about the odd and unusual, so it makes sense.

Yet with the 5212A I did a double and then triple take as I found this watch to be not only modest and practical (thank you, stainless steel) but also beautiful and fun. It feels more open and unrestricted, something that can’t always be said for the very deliberate designs from Patek Philippe.

The Calatrava Weekly Calendar just makes sense as a great watch.

The combination of style, material, and engineering from Patek Philippe is always top notch, but sometimes it lacks frivolity. This piece displays that in spades, noting that people actually like to wear watches. A stainless steel weekly calendar is a super useful timepiece for someone looking to buy into Patek Philippe but still get real use out of a stylish dress watch.

Patek Philippe Calatrava Weekly Reference 5212A

I really appreciate this, and even though it is still way outside my price range, it represents what I would hope to see from the brand that holds one of the coveted “Holy Trinity” positions within the industry. Patek Philippe made a gem with the 5212A, and I’m excited to see if it becomes a trend moving forward!

While we wait to see, let’s break it down!

  • Wowza Factor * 9.4 The wow comes almost entirely from the fact it is a steel dress watch from Patek Philippe!
  • Late Night Lust Appeal * 94» 921.825m/s2 A full calendar watch in stainless steel from Patek Philippe would have any collector pining through the night!
  • M.G.R. * 61.5 The technical advances aren’t lost in Caliber 26 330 S C J SE, it has plenty of upgrades that make this a pretty solid movement from an elite watchmaker!
  • Added-Functionitis * Moderate Having a full calendar that features a calendar week display is very useful, especially for anyone in business that works on projects outlined in weeks (like me). I would definitely recommend regular-strength Gotta-HAVE-That cream for useful horological awesomeness!
  • Ouch Outline * 11.1 Having old fillings drilled out before the local anesthetic has kicked in! If your dentist is in a hurry, sometimes that shot of Novocaine hasn’t quite kicked in and the drilling can be a bit much! Still, I’d happily take the quick start if it meant getting one of the 5212As on my wrist!
  • Mermaid Moment * A Calatrava in steel, with a full calendar?! A day you never thought you’d see, it’s enough to make you say “I do” faster than a feather in a hurricane!
  • Awesome Total * 734 First multiply the diameter of the case (40) with the casing diameter of the movement (26.6), then subtract the unique caliber number after the size designation (330) and the result is a supremely respectable awesome total!

For more information, please visit

Quick Facts Patek Philippe 5212A Calatrava Weekly Calendar
Case: 40 x 10.79 mm, stainless steel

Movement: automatic Caliber 26 330 S C J SE with semi-integrated weekly calendar, Gyromax balance, Spiromax balance spring, 4 Hz/28,800 vph frequency, Patek Philippe Seal
Functions: hours, minutes, (hacking) seconds; date, day, month, calendar week
Limitation: non-limited, regular production!
Price: CHF 29,500

* This article was first published 30 June 2019 at Patek Philippe 5212A Calatrava Weekly Calendar: Patek’s First Production Steel Dress Watch In Decades

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3 replies
  1. J. Quincy Magoo
    J. Quincy Magoo says:

    What a nice write up. Makes me want one. Oh, but wait. Can I get one? Are they available for purchase? Stupid me, what was I thinking? What a racket!

    • Yachtmaster 2021
      Yachtmaster 2021 says:

      Why do you and others always complain that buying a luxury timepiece is more difficult than buying a GSchock? How sad to always be disgruntled. Perhaps you should focus on something more obtainable like world peace.

  2. Maciej
    Maciej says:

    It’s a very cool and good looking watch. Fantastic and consisten typography, a rare thing among watches–including Patek, very often.

    Although calling it a dress watch is a misunderstanding… doesn’t matter if it falls under the Calatrava name, with this specific complication and thus the busy (in a positive way) dial it’s more of an office watch, not a dress watch.


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