At 40 millimetres, the Portofino Perpetual Calendar is the smallest perpetual calendar in IWC's portfolio. This version features stainless steel case, a silver-plated dial, and gold-plated hands and appliques, marking the first time the perpetual calendar is available in stainless steel in the Portofino collection. IWC's legendary perpetual calendar was originally engineered during the 1980s by the brand's former head-watchmaker, Kurt Klaus. The ingenious mechanism is mechanically programmed to ...