Patek Philippe Annual Calendar
Annual Calendar is a wristwatch by Patek Philippe.
First mechanical wristwatch with patented annual calendar. Overall, the self-winding movement Calibre 315 QA and the display of date, day of the week and month requires more components than the known Patek Philippe Calibre 240Q with perpetual calendar: 316 instead of 275. The mechanism is programmed so that it takes account of the different month lengths from 1 March to the end of February. Only then a small correction is necessary.