This issue brings you a unique opportunity—a deep dive conversation with Stefan Ihnen, the long-serving Associate Director of Research & Development at IWC. It’s an exciting moment not only because of Herr Ihnen’s experience but also because this edition introduces some fresh voices to our readers, which is a delightful departure from the usual fare. The world of traditional watchmaking often revisits the same themes, creating a sense of déjà vu. However, engaging with innovative minds in the field reshapes this narrative. While we often hear from big names like Christoph Grainger-Herr or Christiaan Knoop at IWC, I was particularly thrilled to see Stefan Ihnen on the list—largely thanks to another name: Ronan Keating.
Yes, I know it sounds odd to start an article about a watchmaker by mentioning a pop star. Some of you might be cringing at the thought. But before you dismiss this article or toss the magazine aside, let me clarify the connection. Many IWC collectors, especially those of a certain age, will remember that Ronan Keating was once closely linked with the brand and remains a collector of IWC watches. While their official relationship has become a bit murky over time, you can still spot the Irish singer sporting IWC watches on various occasions.
Rewind to 2007 when a significant portion of the IWC management team visited Kuala Lumpur for the grand opening of their flagship store at Pavilion Kuala Lumpur. During that visit, I had the chance to interview then-CEO Georges Kern, but I found myself particularly drawn to a young engineer who was part of the group. Yes, my interests leaned towards the technical from the very beginning. That engineer was none other than Stefan Ihnen, but it took us until this year to finally have an in-depth conversation. After sharing a few light-hearted references to Ronan Keating, we got straight to business.
As we discuss the exciting developments this year, notably the Eternal Calendar, our conversation naturally begins with Stefan’s own journey. A unique blend of watchmaker and engineer, Ihrn honed his skills through IWC’s robust apprenticeship program. He ventured into watchmaking training in Germany, ultimately achieving master watchmaker status in 1997. This meant he was part of a transformative wave in traditional watchmaking that occurred at the tail end of the 20th century and into the dawn of the 21st.
If you’re a fan of IWC’s captivating in-house movements and the innovative materials the brand employs, then connecting with Ihnen is the way to go. He essentially laid the groundwork for the research and development unit, expanding it from its early days. His perspectives on production also shed light on the practical aspects of even grand statements like the Eternal Calendar. Stick around; you might just appreciate his insights on that and to understand how the entire calendar system operates.
Let’s start with your long history with IWC. After all these years, what continues to inspire you?
When I first joined the team, research and development was a small segment. Just a few years later, we expanded that group into movements and cases, with me at the helm of movement development. Back then, I had my hands full with the challenge of building more in-house movements and functionalities. It was an exciting time filled with growth and structuring within the technical department, in addition to working on various movement projects. Initially, we were just eight or nine individuals in the R&D department, and fast-forwarding 20 years later, we’ve blossomed to nearly 50. It’s never been dull! I find motivation at IWC in the continuous flow of new projects—whether it’s a shiny new concept or an evolution in my career and responsibilities.
What’s your favorite aspect of your job?
I have a genuine passion for movement development, even though my current role as Technical Director means I have less time to immerse myself in it as I used to. Nonetheless, I can still dive in on projects that capture my interest. Being part of steering committees gives me the freedom to focus on the areas that excite me. Additionally, my role emphasizes the importance of watchmaking techniques and nurturing the team I work with. It’s genuinely rewarding to see a young apprentice I mentored 20 years ago now leading a team and collaborating directly with me.
As a watchmaker and engineer, how do you navigate the challenges stemming from both perspectives and the differing roles they entail?
You hit the nail on the head regarding the rarity of this dual expertise. In many development sectors, introducing new concepts into production often raises doubts. Questions about feasibility and efficiency frequently arise. This is true not just for watchmakers and engineers but anyone involved in producing components who may prefer to operate seamlessly. When a new idea comes along, the immediate response can be skepticism about its practicality. Overcoming these initial reactions is just part of the role.
For me, there are no conflicts; being both a watchmaker and an engineer is essential. These roles complement each other perfectly in my work, and I actively seek to hire individuals who share this combined expertise for my department. Such talent is indeed scarce, so we often look for young watchmakers who have the potential and desire to pursue engineering studies. This unique blend—of a watchmaker who knows engineering—is invaluable for development, policies, and laboratory work. Having both perspectives enriches our projects significantly.
When it comes to innovation and production, how do you decide where to invest your time and resources? Materials like ceramics and titanium? Or functionalities like chronographs and calendars?
Absolutely, it’s essential to focus our efforts; we can’t pursue every avenue simultaneously. We have established what we call an innovation roadmap, which serves as our strategic guide. We’re dedicated to maintaining our identity and ensuring we stay true to what has made IWC successful. Our founder, Florentine Ariosto Jones, came to Switzerland seeking the means to produce watches on an industrial scale. Accordingly, we aim to create intricate pieces like perpetual calendars and chronographs using fewer components to enhance durability. This doesn’t feel restrictive, but rather serves as a guiding principle.
To be candid, what you’re referring to intersects with marketing and sales as well. Those aspects help shape decisions based on market data and sales performance. What I’m sharing pertains to our overarching vision, defined by our innovation roadmap. Regarding materials, we’re seeing exciting advancements in titanium, ceramics, and our innovative Ceratanium. As for movements, we’re focusing on calendars and chronographs. Notably, IWC is among a select few brands that utilize a digital display for years in our perpetual calendar; we’ve developed multiple moon phase mechanisms and offer a range of calendars—from full to perpetual calendars and now the Eternal Calendar.
The Eternal Calendar builds on the groundwork laid by IWC legend Kurt Klaus in the 1980s regarding perpetual calendars and moon phase functions. At that time, our moon phase accuracy was a one-day deviation in 122 years. Over the years, we’ve improved this to a one-day deviation over 577 years, and proudly, the Eternal Calendar now promises an astonishing one-day deviation over a staggering 45 million years!
You might think that 2100 is far off, but consider that people born today will reach that year—and so might our children and their kids. While the Gregorian calendar could change by the year 4000, we don’t have a clear understanding of what that might entail, even science collaborates on this ongoing inquiry. The Eternal Calendar remains accurate through that far-off mark, which is exceptional, especially since even advanced computers cannot do better. Although 2100 might seem distant, it’s merely a couple of decades away. Watchmakers will need to evaluate by 2080 if they wish to market a perpetual calendar that will remain functional for only 20 additional years. At IWC, we’ll be excited to have the Eternal Calendar in our lineup, knowing traditional perpetual calendars will face their first failure at that point!
Perpetual calendars are crafted to adhere to the structure of the Gregorian calendar. While we explored this extensively in our last issue, let’s quickly recap. Leap years introduce an extra day in February, which occurs in any year divisible by four. However, this system also creates over-corrections. To remedy the problem, the calendar incorporates additional mathematical rules: years divisible by four and 100 are not leap years, although if a year is divisible by four, 100, and 400, it counts as a leap year. As a result, 2100 doesn’t qualify as a leap year, explaining why the year 2000 did. In the case of secular calendars, like IWC’s Eternal Calendar, this issue is effectively resolved. Stefan’s mention of the year 4000 references a proposed change in the calendar that is yet to be universally agreed upon.
This article was originally published in WOW’s Legacy 2025 Issue.
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