PORTUGIESER PERPETUAL CALENDAR 44 IW503702

IWC Schaffhausen’s perpetual calendar was originally developed during the 1980s by former head-watchmaker Kurt Klaus. In 2003, the legendary complication was presented in the Portugieser collection for the first time. Since then, the Portugieser Perpetual Calendar has been a major pillar of the collection.

This IW503702 version features a polished 18-carat Armor Gold® case with a diameter of 44.4 millimeters, an Obsidian dial, gold-plated hands and gold appliques. The watch appears particularly elegant and refined thanks to improved case construction with a thinner casing ring and double-box glass sapphire crystals.

A particular highlight is the intricately crafted dial, which is manufactured in a complex process comprising 60 individual steps. The unusual optical depth is created by applying 15 layers of transparent lacquer, which is fine-ground and then polished to a high gloss finish. The perpetual calendar automatically recognizes the different lengths of the months and adds a leap day every four years at the end of February. All its displays are perfectly synchronized with each other and can be advanced easily via a single crown.

The IWC-typical Double MoonTM display shows the moon as it can be seen from the Northern and Southern hemispheres. Thanks to a special reduction gear, the indication will only deviate from the moon’s actual orbit by one day after 577.7 years. The Portugieser Perpetual Calendar is powered by the IWC-manufactured 52616 caliber movement, which is assembled from 386 individual parts.

The automatic Pellaton winding system features components made of virtually wear-free zirconium oxide ceramic, while the oscillating mass is made of solid gold. Converting the movements on the wearer’s arm efficiently into energy for the mainspring, it reliably builds up a power reserve of 7 days in two barrels. The watch is fitted with a black alligator leather strap from Santoni with an 18-carat Armor Gold® folding clasp.