Ingenieur Perpetual Calendar Digital Date-Month Titanium

Every time the date display advances, IWC’s quick-action switch siphons off a little energy and makes it available at the end of the month. At the end of the year, thanks to the three semi-transparent totalizers, the entire dial is set in motion. The perpetual calendar takes the 29th day of February into account every 4 years, and will remain accurate until 2100.