[Event Video] The story behind the birth of the IWC "Da Vinci" that saved the mechanical watch and the "Portugieser Eternal Calendar"

To commemorate the launch of the Portugieser Eternal Calendar, which was announced at Watches & Wonders 2024, the IWC Talk Show was held at the boutique in Ginza, Tokyo in October. David Seyffer, director of the IWC Museum, and Masamasa Hirota, editor-in-chief of Chronos Japan, spoke about the mechanism behind the watch, which combines a secular calendar with an ultra-high-precision moon phase, as well as the secret story behind the development of the now-legendary original Da Vinci.

Watch the video of the special IWC talk show held at the Ginza boutique

　In the spring of 2024, IWC will announce the Portugieser Eternal Calendar, a watch that will not require calendar adjustment until the year 3900. This watch is truly an epoch-making one, featuring other features such as an ultra-high-precision moon phase display with an error rate of just one day every 45 million years.

　To commemorate the launch of the Portugieser Eternal Calendar, IWC held an "I Love WC Talk Show Event" at its boutique in Ginza, Tokyo in October. David Seyfer, director of the IWC Museum, and Masamasa Hirota, editor-in-chief of Chronos Japan, an IWC enthusiast, took to the stage to discuss the mechanism of the Eternal Calendar and the behind-the-scenes story of the development of the Da Vinci, which popularized perpetual calendars in wristwatches.

Video Contents

0:00 Opening
0:44 Why did IWC focus on developing calendars?
2:50 Perpetual calendar pocket watch developed in 1977
3:20 About Kurt Klaus
4:39 Why was the 1985 release of "Da Vinci" so groundbreaking?
9:47 About IWC calendar watches after the release of the Da Vinci
12:35 The evolution of the Caliber 5000 series
15:48 Announcement of the Da Vinci Perpetual Calendar "Kurt Klaus" and Klaus' retirement
17:43 About the Portugieser Eternal Calendar
19:25 What does Seyfer think makes something "IWC-like"?
21:00 What was the "Plan B" that was considered during the economic downturn of the 1970s?
24: 13 ending

About the IWC Portugieser Eternal Calendar

　This is IWC's first model equipped with a century perpetual calendar, which takes into account not only the leap year that occurs every four years, but also the complex exceptional rules of the Gregorian calendar. Thanks to a newly designed 400-year gear, only years that end with two zeros and are divisible by 400 are treated as leap years. While a typical model equipped with a perpetual calendar would recognize the year 2100 as a leap year, this model follows the exceptional rules and treats it as a normal year.

　In addition, the Double Moon™ display, which shows the moon as seen from both the northern and southern hemispheres, is highly accurate, with an error of only one day every 45 million years.