At SIHH 2012 Cartier unveiled the new Rotonde de Cartier Annual Calendar with the all-new manufacture caliber 9908 MC. All indications are set via the crown, and the 45 mm case is available in white gold or pink gold.
The annual calendar mechanism is incorporated into the plate of the 1904 MC caliber. The in-house design for the movement includes a semi-instantaneous mechanism for converting the large date into two independent numerals (over a one-hour conversion period), which requires less power and so helps to ensure maximum chronometric stability. In this system, the four-branched star-wheel corresponding to the tens column is turned by the catches located on the large unit disc. This unit disc carries within it a simple mechanism which, thanks to a cam bearing a memory of the months incorporated directly into the lightened rims of the units of the date device, makes it possible to display without any possibility of error the months having 30 or 31 days, once the current month has been set.
Aesthetically, the multi-layer dial features on its upper part a silvered “sunray-effect” grid with black transferred Roman numerals, over which pass sword-shaped hands in blued steel. This volume-based arrangement of elements marks out two concentric silvered zones bearing the transferred names of the days of the week (toward the center of the dial), and those of the months (toward the edge). Sliding forward under these shallow recesses, two “hammer-shaped” hands, of which only the red tips are visible, indicate the calendar information which will complete the presentation of the large date, viewed through a double aperture at 12 o’clock. A sapphire caseback allows the movement to be viewed.