Patek Philippe Annual Calendar Moonphase

Overall Condition: Excellent condition overall. Case has been professionally polished. Dial and handset are in equally, excellent condition. Factory strap and deployant show light wear.

In 1991, the soon-to-be graduates at the Geneva School of Engineering were presented with their final project prior to receiving their diploma — to 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 Philippe in collaboration with the bright engineering minds at the GSE. Five years later, Patek debuted the Reference 5035, a watch powered by the world’s first-ever annual calendar movement and one that finally bridged the gap between a triple-date function and the formidable quantième perpétuel.

This slightly later annual calendar, a Reference 5146J-010, is housed in a beautifully proportioned 39mm 18K yellow gold case with a sapphire crystal, signed crown, and a smooth, polished bezel. It features a luminous, sunburst anthracite-toned dial with applied indices, recessed subsidiary registers indicating day and month, a moonphase aperture and date window at 6 o'clock, and a matching luminous 'feuille' handset.

Powered by Patek Philippe's Calibre 315 self-winding movement, it comes complete with a signed alligator leather strap and its signed 18K yellow gold deployant buckle.

This piece packs pedigree, elegance, function and outstanding craftsmanship — exactly what you'd expect from a Patek Philippe!