Patek Philippe Annual Calendar Chronograph Complications – 5905/1A-001

Patek Philippe Chronograph Annual Calendar 5905/1A in a 42mm diameter stainless steel case with olive green dial, which combines two of Patek’s finest complications; the annual calendar function and the chronograph. It features central hours and minutes, a sub-dial at 6 o’clock that is used as a practical 60-minute counter for the chronograph, a central chronograph seconds. And the 3 windows on top for the annual calendar function, with weekday, date and month indications. A small round aperture in the sub-counter is used as a day-night indicator. Powering this watch is the same in-house Calibre CH 28-520 QA 24H, a modern automatic chronograph with an annual calendar module on top. The frequency is 4Hz and the power reserve is up to 55 hours.