Introduction and Launch: The Rolex calibre 1556, introduced around 1965, was a self-winding automatic movement designed specifically for the Day-Date, commonly known as the "President" or "President's Watch." Renowned for its robustness and precision, it featured a dual complication for the day and date display, a hacking seconds function for accurate time-setting, a Breguet overcoil for improved accuracy, and the Microstella regulation system. The Day-Date earned its "President" nickname after General Dwight D. Eisenhower received the 150,000th Officially Certified Rolex Chronometer as a gift. Following his 1952 presidential victory, he was famously photographed wearing his Rolex on the way to his 1953 inauguration. Rolex capitalised on this moment, branding the Day-Date as "the watch worn by Presidents everywhere"—a claim that soon became reality.
