Preview: Up Close With IWC's New Watches 2024

IWC's Watches and Wonders releases as explained by the company's head of R&D

The IWC Portugieser Eternal Calendar

IWC unveiled its new watches for 2024 at Watches in Wonders in Geneva this week, with some eye catching new models. Most eye-catching among them: the 44mm IWC Portugieser Eternal Calendar, a day, date, month, year, and moonphase watch that can account for leap years and leap year exceptions. (Leap years occur every four years but are skipped in years that are divisible by 100 but not 400. The next three skipped will be 2,100 AD, 2,200 AD, and 2,300 AD.) In all, IWC boasts that the Portugieser Eternal Calendar is guaranteed to be accurate until the year 3,999 AD.

“It's really sad, we would've gone further,” said Christian Satzke, head of research and development for movements at IWC. “But for the year 4,000 it's not defined whether this will be a Leap Year or not.”

IWC’s watchmakers were able to accomplish this impressive feat thanks to the the R&D team’s development of what Satzke called “the slowest moving part in any of our IWC watches.”

“It does a rotation of 0.9 degree per year in order to achieve these 400 years for one revolution,” said Satzke.

Not tied to the arbitrary decision about the year 4,000 AD’s leap year status, the moonphase has an even longer guarantee of accuracy of 45 million years. Satzke said IWC is applying for a Guinness World Record for the accomplishment, which beats out the current record holder by about 43 million years.

The IWC Portugieser Eternal Calendar