As you read this issue, a titan of watchmaking will have just celebrated his 90th birthday. Plenty of watches make it well past this mark but this reminds us that mere mortals often do not, even an august personage such as Kurt Klaus. In a leap year that sees the WOW team pay special attention to perpetual calendars, we were nevertheless surprised to learn of this momentous occasion while doing research on the aforementioned complication. Klaus is, of course, most famous for his seminal work on the perpetual calendar for IWC, where he made a mark that is still felt today. If you have an IWC perpetual calendar from the Klaus era onwards, you bear testament to this legacy. 

The perpetual calendar at IWC has two distinct phases – before Kurt Klaus and after Kurt Klaus. As noted in our special in the Autumn issue of WOW, the perpetual calendar has not had many significant developments in the last 100 years. One of the few developments worth taking note of was Klaus’ work in 1980s. According to IWC and plenty of published reports, Klaus was IWC’s head watchmaker in the early 1980s, and he had it in mind to do the unthinkable – improve on the mechanical perpetual calendar. To cut the suspense, this would go on to become the criminally underrated Da Vinci Chronograph Perpetual Calendar in 1985. Them’s fighting words, as they say, but it all makes sense when you consider that the all-indications-adjusted-by-one-crown system emerged from this multi-complication. 

Of course, that means all the contemporary IWC perpetual calendars, including the four that debuted at Watches and Wonders Geneva in April, share this characteristic. The brand once again notes what a boon this system is for users. To explain a little here, before Klaus’ innovation in the 1980s, each calendar indication – including the moon phase – had its own adjustment mechanism. This was usually a recessed pusher on the case flanks, and plenty of perpetual calendars maintain the same system even now. So, if your perpetual calendar winds down and you leave it alone while wearing other watches, you will then have to adjust each calendar indication forward to the right ones. If you have left the watch alone for a long while, this can get quite tedious. 

Quick-Setting

Kurt Klaus figured out the logical solution here, using the very grand lever that kept all indications synched up in the course of normal running. He proposed synchronising all the calendar information such that adjusting one element automatically adjusts all the others. So, if the 24-hour wheel is advanced by the user to the tune of one full revolution, the day, date, moon phase and year also advance accordingly. As a quick note, this is not the same as setting the date by advancing the minute hand 24 times…calendar adjustments are done at position one of the crown while time-setting is at position 2. That is precisely what you will find in the four Portugieser Perpetual Calendar 44 watches, all new for 2024 — but this is also true of every other kind of perpetual calendar in the current IWC families. These four watches will serve to illustrate the qualities of IWC perpetual calendars, and they happen to be in the same collection so they share other characteristics besides. 

All are approximately 44.4mm and 14.9mm thick, with the signature barely-there Portugieser bezel. This means there is a lot of dial real estate for the many indications of the IWC perpetual calendar, including the signature double moon phase at noon. Arguably, the Portugieser aesthetic is the best of all for the information-heavy perpetual calendar so you might be surprised to learn that this classic complication only debuted in the collection in 2003. The Big Pilot is a good fit too but that family looks its best with just the basics on the dial.

On that note, what do we have on the dial of these perpetual calendars then? Starting with the moon phase display is actually of the state of the moon’s phases as seen in the northern and southern hemispheres. At 3 o’clock, we find the date and power reserve within the same subdial, while at 9 o’clock, the day of the week shares another subdial with the running seconds. At 6 o’clock, the month indication is on its own. As usual, these displays create a subtle harmony on the dial, overall. Somewhat off by itself is the digital year display, at 10 o’clock.

Establishing a Legacy

Hard at work beneath the dial (the Horizon blue variant is a joy to behold in person) is the calibre 52616, which consists of a base movement with a long power reserve (7 days) and the perpetual calendar module dial-side alongside the motionworks. It is this calendar system that marks the genius of Kurt Klaus and establishes his legacy, as noted earlier. To return to that story then, Klaus figured out that the calendar system could be simplified and that it would be a great boon. As a result, calibre 52616 has something like 385 components but only 81 of those are related to the perpetual calendar module. According to IWC, Klaus had the idea of making the calendar module separate from the base movement. He also knew that by synchronising the calendar indications, including the moon phase display, he could do away with the standard correctors that afflicted most perpetual calendars. This would reduce the number of parts, allow for more robust cases and improve the user experience. For IWC, this represents something ideal, or close to it, because the brand has built up a reputation as a maker of tool watches.

Looking at the current crop of four watches, you might not immediately think ‘tool watch’ when you look at one. Like the other Horizon Blue and Dune dial variants, these Portugieser watches are cased in white gold. As for the Obsidian and Silver Moon dial variants, they are cased in Armor Gold. All four dials are not galvanised or PVD treated and the like. They are actually executed with 15 layers of transparent lacquer, further elevating the watches past the point of tool watches. Hammering home this point are the gold applique numerals, which are applied by hand. All told, IWC says there are up to 60 steps in the making of the dials.

Other details about the watches also belie notions of pure functionality. These include the Santoni alligator straps, which are in four matching shades, and the double box-glass sapphire crystals. Unusually, the hands of each model are gold-plated (rhodium for the Horizon Blue watch) rather than being solid as one might expect. This might get revisited later so look for changes in the specifications of these models if they make you do a double-take but have not yet made you pull the trigger. Pricewise, all the gold models here are north of SGD 60,000, which is good relative value. 

This article will appear on WOW’s upcoming Legacy Issue

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