Notes: There have been a few distinctive versions of the 6511 since it was first introduced – notwithstanding minor differences. This very first Day-Date model is said to be somewhat flawed movement-wise, notably the day & date change causing lag in the movement making the overall performance less-than noteworthy.

Rumour has it that the very first Day-Dates made their appearance in 1955, the same year the patent was filed. Supposedly these were delivered only to the Italian market – more or less prototypes, with the ever watch-crazy Italians serving as guinea pigs. To be frank, I wouldn’t be surprised if this story turned out to be completely flawed. However, these should have a few distinctive marks;

Mechanism: First Rolex Day-Date movement. Introduced 1956. The Day-Date ref. 6511 (or “President” as the model came to be popularly known) debuted in 1956 with calibre 1055 beneath the dial. This movement does not have a "quick-set" feature as that was introduced in the 3155 movement in 1988.

Family Notes: The Rolex Day-Date was introduced in 1956. It soon became known as the "Rolex President". It was unofficially renamed after President Eisenhower became associated with this model watch. This association was made as the watch was known to have been worn by LBJ and shared a scandalous connection to JFK. Since then it has earned the vote of a diverse array of potentates, including Warren Buffett, Jay Z, and (fictional character) Tony Soprano. In 1977, Rolex started using the new (at the time) 3055 movement for the Day-Date/President line. As of 2018, the Day-Date 40 uses the 3255 movement.