Whether they’ll admit it or not, despite their Protestant roots, the Swiss watch titans have always cast themselves in the mold of the Greek Gods, a pantheon of horological divinities dwelling in the seclusion of their Genevoise Mount Olympus crafting rare mythical timepieces which they deign to bestow upon us mortals, if and when the mood strikes them.

But if Kurt Klaus, the legendary former technical director IWC was a Greek mythological figure he’d be Prometheus, the bringer of light and enlightenment to humanity. Because previous to 1985 the perpetual calendar was a revered, coveted rare but fragile complication. Something to be kept in a safe and gazed at periodically in fanatical devotion.

IWC global brand ambassador and living legend Kurt Klaus
IWC global brand ambassador and living legend Kurt Klaus

As detailed here, this complication automatically compensates for the shifting rhythms of the 30/31-day cycle of the months throughout the year. But more importantly, it also automatically compensates for the 28 days of February and even knows when to add the extra day on the 29th on the leap year. Imagine a watch that can provide you day, date, month, leap year and phase of the moon at all times, as long as you keep it wound. But the challenge occurs when you don’t wind your watch and it stops. Then you have to use a series of fidgety pushers, integrated into the case, and a stylus to correct each and every one of these indications individually. Worse, in most perpetual calendars if you accidentally try to adjust it during the date changeover period, you can jam or damage the movement badly.

Ref. 5250 moon phase pocket watch
Ref. 5250 moon phase pocket watch

In Klaus’ mind there had to be a better way. A few years earlier he’d specialized in making calendar and moonphase pocket watches at IWC. Bear in mind that in the late ‘70s the entire Swiss watch industry was convinced that battery powered quartz watches were the future. But nonetheless IWC felt compelled to keep mechanical watchmaking alive. Klaus recalls, “I made a moonphase pocket watch, a simple calendar. I was lucky because, although most companies would have thought it crazy to produce a mechanical watch at this time, IWC decided to experiment and make a limited edition of the watch. We made 100 pieces, just to see if there was any demand. We presented them at the Basel Fair in 1976 and they sold out in record time. It was excellent motivation to continue developing. The Sales Director Hannes Pantli came to me and said: “Stop with pocket watches, they are out of fashion. Now do the same in a wristwatch.” This was the birth of the Da Vinci Perpetual Calendar.”

IW3750

Because Klaus immediately began to visualize not a simple calendar wristwatch but a perpetual calendar with one big difference: Rather than having all the irritating pushers he wanted all the indications controlled by the same crown used to set the time. But this was in an era where all his calculations had to be done manually. Says Klaus, “When I made the Perpetual Calendar, I didn’t know exactly what a computer was. I made all my sketches on the drawing board. I made the prototypes and after manually making the calculations.” But more than a better, easier to use watch, Klaus wanted to make his complication easier to produce, to make it more accessible to a whole new generation of customers. He explains, “I like to call it the new generation of a perpetual calendar – I wanted to make one that could be produced in serial production. And this is the heart of IWC. We never wanted to make uniques pieces. For IWC, the watch industry is important not the individual watch, so I tried to make the calendar for industrial production, as well as with a system that was easy to use.” After endless of hours of contemplation and calculation he created a module that included not just day, date, month, leap year but also a four-digit year indication and a moonphase display that was accurate to 1 day in 177 years. And it was relatively simple to produce and a breeze to use.

Caliber 79261 perpetual calendar module used in the groundbreaking IW3750

At the same time IWC’s designer Hano Burtscher had dreamed of a watch case inspired by Leonardo da Vinci’s recurring circles in his plans for a harbor fort in Piombino from 1499. Together they created the Da Vinci perpetual calendar reference 3750.

The Da Vinci’s sketches for the harbor fort at Piombino was the inspiration for IWC’s Da Vinci case design
The Da Vinci’s sketches for the harbor fort at Piombino was the inspiration for IWC’s Da Vinci case design

1985 IWC Da Vinci Perpetual Calendar Chronograph Ref. 3750

Launched in 1985, the Da Vinci was a total revelation, an act of brilliant Promethean enlightenment. Because the resulting watch fitted to a Valjoux 7750 chronograph base, was not just the most user friendly perpetual calendar ever made, it was also its most avant gardist in design and its most accessibly priced.

The success of the Da Vinci and the shockwaves it generated completely changed the perception of IWC into one of watchmaking’s most innovative brands.

IWC Perpetual Calendar Da Vinci — Ref. IW3750 (1985)

1986 IWC Da Vinci Perpetual Calendar Chronograph Ceramic Case Ref. 3755

Says Klaus about the watch’s success, thanks to its brilliant adjustment system and its accessible price, “These two things together made it a huge success. After two years, IWC’s annual production was 2,000 perpetual calendar wristwatches — more than the rest of the industry put together.” Amusingly because they were only expecting an order of 10 to 15 watches rather than the hundreds of orders they received IWC realised they had ordered inadequate gold for the cases. So instead of stamping and machining the cases, which creates large amounts of waste, they pioneered the technology to cast them in gold. This process gave them the idea for another technical breakthrough.

IWC White Zirconium Oxide — IW3755 in white ceramic (1986)
IWC White Zirconium Oxide — IW3755 in white ceramic (1986)

Not content to rest on his laurels, just one year later in 1986 IWC unveiled the Da Vinci perpetual calendar chronograph with the Swiss watch industry’s first use of zirconium oxide ceramic. The idea of a ceramic watch case was a hugely ambitions one. It made sense because after diamond ceramic is the world’s hardest substance making it essentially scratchproof. To achieve this IWC had to pioneer the technology for molding and then machining these cases to the right specifications. The resulting watches with both ground breaking movements and ground breaking case technology are some of the most distinct, historically significant and collectable watches in modern history.

IWC Black Zirconium Oxide — IW3755 in black ceramic (1986)
IWC Black Zirconium Oxide — IW3755 in black ceramic (1986)

1995 Il Destriero Scafusia and Da Vinci Split Seconds Chronograph Perpetual Calendar

The Da Vinci continued to be a showcase for IWC’s innovation and in 1995 it became the home of the brand’s first split seconds chronograph perpetual calendar.

2000 IWC Da Vinci Tourbillon Perpetual Calendar Chronograph Ref. 3752

In 2000 with reference 3752 IWC unveiled its first perpetual calendar chronograph tourbillon, a remarkable achievement and an absolutely breath-taking masterpiece of high watchmaking.

The Portofino Perpetual Calendars

From left: IWC Portofino Ref. 3541 and IWC Portofino 2050 Romana Perpetual Calendar Platinum
From left: IWC Portofino Ref. 3541 and IWC Portofino 2050 Romana Perpetual Calendar Platinum

Kurt Klaus’ amazing perpetual calendar was also used in non-chronograph versions in IWC’s beautiful round classic and slim Portofino family and the resulting watches were magnificent to behold. Of particular significance is reference 3541 dating to 1989 and reference 2050, which at the time of its introduction in 1995 was the world’s slimmest perpetual calendar at only 3.1 mm in height. If you are interesting in these amazing watches, Revolution has sourced one example each of these rare beauties each backed by our 15 month warranty.

Each of these watches demonstrates that Kurt Klaus created a perpetual calendar that could be expressed in arresting and uniquely different ways in different models across IWC’s product line. But this would be just the beginning as over the next 33 years this complication would become an icon representing IWC’s dedication to brilliant functional innovation. Let’s take a look in how it looks in other IWC families.

Portuguese Perpetual Calendar

Today the model IWC’s perpetual calendar is most associated with is the sublime Portuguese Perpetual Calendar. First introduced 2003, the movement featured an improvement in the moonphase indicator resulting in it only being one day off in 577 years vs 177 in Da Vinci. Even more important is that with this model IWC combined Kurt Klaus’ ultra easy to use perpetual calendar with the brand’s legendary 7 days power reserve 5000 automatic caliber. Because this watch usually holds a full week’s worth of power and because of its ultra efficient Pellaton winding system, as long as you wear it one day per week, you’ll never need to adjust it again.

This model has been the focus of subtle evolution related to slight enlarging of the case and also the use of a super cool double hemisphere moonphase indicator. The rationale behind the indicator is the following: If you look at the night sky the moon looks one way from above the equator and the complete opposite (upside down) from south of the equator. The problem is that 99 percent of watches use only a northern hemisphere moonphase equator. But for those of you residing in Australia or Brazil you’d be out of luck. Thanks to the Portuguese Perpetual Calendar you can now see the phase of the moon for the northern and southern hemispheres simultaneously. We are pleased to offer the following Portuguese perpetual calendars with both traditional and double hemisphere moon indicators, all backed with our 15 months warranty.

Ingenieur Perpetual Calendar Chronograph

The Gerald Genta design Ingenieur watch was launched following the success of Audemars Piguet with its Royal Oak and Patek Philippe with its Nautilus, both also designed by Genta. Today the early examples of the this watch dating back to 1976 are some of the most collectable vintage watches around. The modern version of this watch is a showcase for IWC’s technical language and was fittingly the first watch to feature the brand’s “digital perpetual calendar” where month and date are shown in grand date formats using two sets of overlapping discs. The result is a watch that bristles with modern aggressivity complimented by the use of a high tech titanium aluminide case.

GST Perpetual Calendar Chronograph

IWC GST Perpetual Calendar IW3756-03 (2001)
IWC GST Perpetual Calendar IW3756-03 (2001)

The GST or “Gold Steel and Titanium family” was made from 1998 to 2004 and remains one my favorite IWC models. It follows the Porsche design watches and takes many of its ultra clean modernist touches from this collaboration. Of the various complications one of the coolest is the titanium case GST perpetual. In many ways this watch is an absolute showcase for everything that IWC does best. The case and bracelet are made from titanium, a material that IWC pioneered the use of in the watch industry. The movement is the incredible perpetual calendar chronograph first launched in the 1985 Da Vinci, the most robust and reliable complication of this kind on the market. And the yellow and black styling comes from IWC’s famous Deep One dive watch, the first wristwatch with a mechanical depth gauge indicator. As a value proposition this watch is extraordinary and also happens to be the very first perpetual calendar I’ve ever purchased.

Pilot and Flieger

IW3757 Pilot’s Watch Chronograph Perpetual Calendar Wempe (2003)
IW3757 Pilot’s Watch Chronograph Perpetual Calendar Wempe (2003)

Some of the most charming and highly coveted IWC perpetual calendars have been executed in the brand’s pilots cases, specifically the Flieger Chronograph and the Big Pilot with 7 days power reserve.

The first Flieger Perpetual Chronograph was released as a limited edition in 2003 for German retailer Wempe in 42 steel case, reference 375701. This was followed by watches created for Singapore retailer Sincere watch reference 375702 with Spitfire dial in white and 375703 Spitfire dial black both featuring 42mm steel cases.

Big Pilot Perpetual Calendar in rose gold (2012)
Big Pilot Perpetual Calendar in rose gold (2012)

The Big Pilot Perpetual Calendar was also launched in 2003 initially as a 50 pieces limited edition with titanium cases made for the US retailer Cellini. This was followed by a limited edition in platinum for Sincere Watch and then a for Bucherer in rose gold.

IW502903 Big Pilot Perpetual Calendar Top Gun Boutique (2013)
IW502903 Big Pilot Perpetual Calendar Top Gun Boutique (2013)

There is also a 2012 boutique edition rose gold with gold dial. However in recent years our absolute favorite executions of the Big Pilot perpetual calendar is the stealthed out Top Gun 250-piece boutique edition featuring a ceramic case and a black dial with red markers. Incredibly, Revolution has this exact watch available here and backed by our full 15 months warranty.

Da Vinci

IW3762 Da Vinci Perpetual Edition Kurt Klaus Rose Gold (2009)
IW3762 Da Vinci Perpetual Edition Kurt Klaus Rose Gold (2009)

Over the years the Da Vinci has gone through different case shapes. And though the current case shape features a round body with mobile lugs more in alignment with the 1985 reference 3750, from 2007 to 2016 the Da Vinci was created as a tonneau-shaped watch inspired by the early Da Vinci watches from the ‘50s. This soon became the home of the famous perpetual chronograph and it was in the case that the brand released the a limited edition dedicated to Kurt Klaus and with the great man’s portrait engraved into the case back. From a value perspective this represents one of the most accessibly priced complicated watches in the world.

IW3921 Da Vinci Perpetual Calendar (2017)
IW3921 Da Vinci Perpetual Calendar (2017)