Comparing the old and new IWC Portugieser Perpetual Calendar

calendar | ic_dehaze_black_24px By Monochrome | ic_query_builder_black_24px 7 minute read
IWC Portuguese Perpetual Calendar Steel full

We at Monochrome obviously love IWC watches. Especially when it comes to their iconic pieces. The IWC Portuguese Perpetual Calendar is such a piece. First introduced in 2003, this watch has been subject to minor changes every couple of years, without dramatically changing its recognizable identity. So, it’s now time for us to compare the brand new 2015 edition with the previous version, and to see what changes can been seen – or maybe be unseen?

Throwback – The Perpetual Calendar by IWC Watches

IWC Portuguese Perpetual Calendar Steel dial detail
IWC Portuguese Perpetual Calendar Limited Edition in stainless steel

How did the perpetual calendar by IWC get its iconic status? When you are trying to understand why a watch gained so much fame, you have to understand its historical importance. In the case of the IWC Portuguese Perpetual Calendar, this importance was not actually gained by a Portuguese watch, but rather by the Da Vinci Perpetual Calendar, a watch that rather shocked the industry. This Da Vinci Ref. 3570 was first introduced in 1985. For IWC, it was the launch of the perpetual calendar movement into wristwatches. The man behind it was Kurt Klaus. During the mid-1970s, when the Swiss watch industry was hugely affected by the quartz crisis, Kurt Klaus was creating a simple calendar mechanism that had to be fitted on top of a pocket watch movement. When he finished the watch in question, he presented it to IWC, which was impressed by his accomplishment – and later decided to produce it. Kurt Klaus was in charge of the prototyping, the design and the production of the watch. The market for pocket watches however decreased very quickly and at the end of the 1970s, pocket watches were almost gone.

IWC Portuguese Perpetual Calendar Steel dial close

Because of that, IWC had to focus on wristwatches. IWC approached Kurt Klaus to create a calendar mechanism again. While he was busy with his previous project, he obviously gained a lot of experience in the field of design, production and prototyping. Thus, Klaus felt he could create something more complicated and wanted to add something extra special. Thus, he didn’t create a simple calendar mechanism, but the perpetual calendar mechanism that is now featured in the IWC wristwatches. This mechanism also had to be fitted on top of an existing movement. However, at that time, most perpetual calendars had to be adjusted via multiple pushers, something mister Klaus didn’t approve. He wanted the movement to be easy to set and all adjustments had to be done by the crown. The idea was actually to fit the mechanism on a Jaeger-LeCoultre movement, but Günter Blümheim came up with the idea to design the watch with a chronograph as base-movement – and you have to imagine that all of this had to be done without the help of any computers, which makes it quite an achievement.

IWC Portuguese Perpetual Calendar Steel full case

Now we know why the perpetual calendar watches by IWC are special. However, what makes the IWC Portuguese Perpetual Calendar so special? Of course, the movement mentioned above participates (even if the Portuguese doesn’t feature a chronograph as base movement, but rather the famous 7-day movement). It basically is the same module as used in the Da Vinci. Only the size of the mechanism is different, as well as the accuracy of the moon phase complication (one day off in 122 years for the Da Vinci vs. on day off in 577 years for the Portuguese). You also have to realize that the Portuguese is a collection known for its stylish, classic and timeless design. Combining the classical looks of the Portuguese with the amazing perpetual calendar movement creates an interesting combo.

Now we are in the year 2015 and that’s special for IWC, as it is the 75th anniversary of the Portuguese. Because of this, IWC decided to add new watches into their collection, like the Annual Calendar and the anniversary pieces (here and here). Besides introducing a couple of new watches, they also upgraded a few watches, including the Portugieser Perpetual Calendar (note the change of name…). What changes can you expect? Let’s have a more detailed look.

The 2015 IWC Portugieser Perpetual Calendar Ref IW5033-01 (in 18k white gold)

What are the changes? Well, there are quite a lot of differences, design-wise and movement-wise. In short, the differences are:

The name – Portuguese vs. Portugieser

The previous version was named the “IWC Portuguese Perpetual Calendar” – the new one is named “IWC Portugieser Perpetual Calendar”. IWC goes back to the original German name.

The movement – calibre 51613 vs. calibre 52610

While the previous version was powered by the 51613 caliber, the 2015 edition features the 52610 caliber. The new version now features a twin-barrel system, instead of a single barrel ensuring the power reserve – always with 7 days of power-reserve but with a better stability over the full range of power.

The rotor is also different. The new rotor is now executed in 18k gold instead of stainless steel and it shows a partially skeletonized shape, with beveled angles.

Some technical parts are also improved, including the winding pawls and automatic wheel made of black ceramic. Rotor bearing is made of white ceramic. All of this for a better resistance and reliability because ceramic is practically wear-free. There’s now an Index-less balance with an increased frequency of 4 hertz (28,800 beats per hour) combined with a Breguet spring.

The overall movement had been redesigned with new bridges, more open to have a better view on the technical elements. Finally, there’s a nicer finish, with beveled angles on the bridges and more details on the gears, bridges, wheels, screws (now blued).

Old edition on the left, new edition on the right.

The lugs

When comparing the lugs, you can see that, on the latest edition, the lugs are shorter and also more curved. This might seem like a small change, but the feel on the wrist is quite different. The watch feels more balanced on the wrist and better adjust (even on smaller wirsts), making it easier and more elegant.

Old edition on the left, new edition on the right.

The crystal

The 2015 version has a box-type sapphire crystal, while the old one has a flat sapphire crystal. Thus, it allows to have a slightly thinner bezel on the 2015 edition of the IWC Portugeiser Perpetual Calendar and a thinner profile.

Old edition on the left, new edition on the right.

The logo on the dial

Looking at the dial of both watches, you can see that on the previous version the name IWC Schaffhausen was written with a curve. This is different on the new one, which is written in a straight line.

Old edition on the left, new edition on the right.

The strap

While the previous edition came with a dark brown alligator strap by IWC, the 2015 IWC Portugeiser Perpetual Calendar comes with a black alligator strap by Santoni.


Taking all the changes into consideration, it is fair to say that the watch is updated pretty massively, even if most of these changes remains very subtle (or invisible). It is interesting to witness that a watch can go through so many changes without losing track of its identity. Looking at both watches, we have to admit that it remains an update and not a new watch – which is clearly not that bad.

Talking about the price, we have to compare the price of white gold versions (and not the stainless steel edition photographed here, priced much lower). The previous version in white gold is currently priced at 34,100 Euros and the new IWC Portugeiser Perpetual Calendar version in white gold is priced at 41,200 Euros. (The Limited Edition in stainless steel is priced at 25,600 Euros).

I would like to thank Dale Vito Boom for his article on the various IWC Portuguese Perpetual Calendar models, that served as guideline and inspiration for my article. 

2 responses

  1. Nice read, thanks. I would like to see the pictures less dark, so work on those skills as well please.

    (ps , will you consider Disgus as your forum respons tool ?)

  2. Can you describe changes in the display of the moon phase? When did IWCeliminate the dual hemisphere “side by side” moons, giving thems somewhat of a “figure 8” appearance?

    I am preparing to purchase a pristine, nearly NIB (model IW502107) Portuguese Perpetual Calendar and am concerned after learning about the updated technology in the newer versions made after 2015. Should I be concerned about the technology updates mention in this article?

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