As we told you last week, IWC will be debuting an overhauled Portugieser collection at SIHH. For their new Annual Calendar, IWC needed to develop a new automatic movement.

The result is an in-house caliber 52850 which runs at 4Hz, has 36 jewels, and boasts a 7-day (168-hour) power reserve. The new caliber features upgrades that will be seen across the entire 52000 caliber family. Including a slimmer rotor, and bridges that are more open – allowing more details to be visible through the open caseback. The bridges are inset with a solid gold “Probus Scafusia” medallion. There is also an improved Pellaton winding system with a virtual wear-free component made of black and white ceramic.

IWC Portuguese Annual Calendar close-up

While the movement is complicated, the dial layout is anything but. The purist design features a triple calendar indication (at 12 o’clock) for the month, date and day, each with its own aperture. In addition, the watch displays hours and minutes via the centrally mounted subsidiary dials for small seconds (at 9 o’clock) and the remaining power reserve (at 3 o’clock).

The calendar switching mechanism automatically adjusts for the different number of days each month, however, unlike a perpetual calendar, it is unable to make the adjustment for February or take into account if it is a leap year. Therefore, it needs to be manually corrected once in February, and once during a leap year.

According to IWC, “For the development of the annual calendar module, IWC’s watch designers ensured that the correction could be carried out easily and conveniently using the crown. Thanks to this elegant solution, the engineers were able to dispense with a corrector, which would have compromised the Portugieser Annual Calendar’s purist design.”

The crown is non-locking, polished, and features a relief engraved “Probus Scafusia” logo. And, thanks to the innovative movement design, no recessed caseband pushers are needed to correct the annual calendar. Instead, all functions are controlled by the crown.

The IWC Portugieser Annual Calendar is available in steel, in either a midnight blue (Ref. IW503502) or a silvered dial (Ref. IW503501), and in 18K red gold with a silvered dial (Ref. IW503504). The case measures 44.2 mm by 15.3 mm and is fully polished with a thin fixed bezel

All three references come with a black alligator strap and folding clasp. The water resistance is rated to 30 meters. An arched edge sapphire crystal with anti-reflective coating on both sides protects the dial.


Photos by IWC.

Posted by:Jason Pitsch

Jason is the founder of Professional Watches and specializes in writing, product photography, and digital marketing.