Patek Philippe Annual Calendar Moonphase

Overall Condition: Excellent condition overall. Case shows light signs of wear. Dial and matching handset are excellent.

In 1991, the soon-to-be graduates at the Geneva School of Engineering were presented with their final project prior to receiving their diploma — simplify the perpetual calendar.

Although the task was easier said than done, their work led to the inception of the annual calendar complication, patented by Patek in collaboration with the bright engineering minds at the GSE. Five years later, Patek debuted the Reference 5035 which marked the world’s first-ever annual calendar movement and finally bridged the gap between a triple date function and the formidable quantième perpétuel.

This piece transports us forward to the present day and is a handsome modern interpretation of the Patek Philippe Complications Annual Calendar. Designated as a Reference 5205R-011, this lovely timepiece features a 40mm 18K rose gold case with sculpted, hollowed lugs, a concave bezel, and polished finish.

The olive sector dial features a set of applied rose gold indices and presents a set of day-date-month apertures at 12 o’clock, a subsidiary pointer-date dial with a moon phase display and a 'dauphine' handset. This dial color is one of the most unique on the market, and definitely adds a lovely personality to the right outfit.

The back side features an exhibition back providing a window to admire the self-winding movement and its 21K gold winding rotor adorned with the hallmark Patek Philippe seal. It comes fitted to a signed alligator strap with a matching 18K rose gold pin buckle. This piece is also accompanied by its box set, leather folio, books, and Certificate of Origin.

There’s no doubt the Nautilus and Aquanaut have gotten their time in the sun, and even vintage Patek Philippe in general continues to demand the attention of any savvy collector. But let us not pass over the high-complication heavy-hitters hiding in plain sight in Patek’s modern catalog!