In 2000, a new IWC seven-day automatic movement, calibre 5000, was introduced in an important new Portugieser model. In 2003, IWC then combined that movement with its special perpetual calendar module, producing the first PPC, reference IW5021.
Unlike the traditional Portugieser design, the heritage of IWC’s perpetual calendar module differed. While perpetual calendars – watches that show at least the day, date and month while accounting for different month lengths – have long been part of Swiss horology, IWC developed something more innovative and practical.
In 1985, IWC introduced an ingenious perpetual calendar module that only used the crown to reset all functions since the calendar indications were integrated. This complex mechanism, created by IWC’s renowned master watchmaker Kurt Klaus, was used initially in an Ingenieur model and, then, a few months later, as a Da Vinci model, reference 3570. Klaus realized that all day, date, month, year and even moon phase functions are related to each other, and all could be set simultaneously by the crown. The technical design was complex, but its use was simple and the result was simply brilliant.