The Watch: Patek invented the annual calendar in 1996 and patented it. The idea was practical: a calendar that knows the difference between 30 and 31 day months and only needs correcting once a year, at the end of February, without the cost and fragility of a full perpetual. It filled the gap between a simple date watch and the perpetual calendars that had defined the brand for decades, and it became one of Patek's best-selling complications.
The 5396 arrived in 2006 for the complication's tenth anniversary and rethought how the information gets displayed. Earlier annual calendars used three subdials. The 5396 puts the day and month in twin in-line apertures beneath 12 o'clock instead, a layout pulled from the perpetual calendar references 3448 and 3450 of the 1960s. It cleans up the dial enormously, and plenty of collectors call this the best-looking annual calendar Patek has made.
The case is 38.5mm in 18k white gold. The silver opaline dial carries applied baton markers, a date aperture and moon phase sharing the subdial at 6 o'clock, and a 24 hour indicator. Inside is the caliber 324 S QA LU 24H, and here's a piece of trivia worth knowing: Patek's annual calendar actually uses more components than its perpetual, 324 parts against 280, because of how the month-length programming is built. The movement is visible through the sapphire caseback.
This example comes on its original strap and deployant clasp in good condition with some light marks. Watch only. It will be tested and authenticated upon purchase.
