Patek Philippe Annual Calendar Regulator

Overall Condition: Great condition overall showing only light signs of wear consistent with age and use.

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 Philippe in collaboration with the bright engineering minds at the GSE. Five years later, Patek debuted the Reference 5035 — the watch that 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 example, a Reference 5235/50R-001, features a neat ‘regulator’ display for optimal legibility and is housed in a sleek, 40.5mm 18K rose gold case with a sapphire crystal, a signed crown, and a smooth, polished bezel. It features a vertically brushed, black/ gray satin-finished dial with a pair of recessed subsidiary registers indicating hour and minutes, as well as day and month apertures flanking the 12 o’clock marker and a central seconds hand.

Powered by Patek Philippe's Calibre 31-260 self-winding micro-rotor movement, it comes fitted to its signed, black alligator leather strap with a signed, 18K rose gold pin buckle and includes all of its factory paperwork.

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 why not zig when everyone else zags with this high-complication, heavy-hitter from one of the best watchmakers on the planet!