Notes: This is a Rolex 36mm Day-Date president. Unfortunately I haven't been able to find out much about it. I do know it uses a 3055 movement.

Mechanism: The Cal. 3055 released in 1977, it formed part of the 3000 series of movements that ushered in the high beat frequency era, giving the emblematic flowing seconds hand of all latter day Rolexes. It was the fifth generation Rolex Day-Date movement The Cal. 3055 brought many changes for both the day and the date functions but, as a single Quickset movement, only the date could be adjusted with the crown An unusual aspect of the Cal. 3055 is, unlike the vast majority of Rolex’s engines, it was only ever used in one model of watch. This was the 1977 edition of the 18038 Day-Date.

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.