Patek Philippe Annual Calendar Regulator 40.5mm White Gold Self-Winding

The Patek Philippe Annual Calendar Regulator Ref. 5235G-001 represents groundbreaking complications engineering from Geneva's oldest manufacture. This 40.5mm timepiece in 18k white gold features regulator-style display separating hours, minutes, and seconds into distinct subdials. Annual calendar complication displays day, month, and date requiring adjustment only once per year at February's end. Manufacture Caliber 31-260 REG QA ultra-thin automatic movement delivers 48 hours autonomy with 22k gold micro-rotor. Sapphire exhibition caseback reveals Spiromax hairspring and Pulsomax escapement in silicon.

Reference 5235G debuted at Baselworld 2012 as Patek Philippe's first regulator-style wristwatch combining annual calendar functionality. Caliber 31-260 REG QA evolved from micro-rotor 240 base with extensive reworking. Movement beats at 23,040 vph providing superior rate precision versus standard 28,800 frequency. Silicon components include Spiromax balance spring, Pulsomax escape wheel, and anchor forged from Silinvar material. Three apertures display day at 10-11 o'clock, month at 1-2 o'clock, and date at 6 o'clock center. Hour subdial positions at 12 o'clock with small seconds at 6 o'clock while central sweep hand indicates minutes.

Case design draws inspiration from perpetual calendar reference 3448 with angular lugs and mixed finishing. Polished bezel and lug tops contrast brushed caseband creating sharp architectural profile. Two-tone silvery dial features vertical satin finish with navy blue printed indications enhancing legibility. Railway minute track surrounds dial perimeter. Patek Philippe Seal certification ensures movement finishing and precision standards. This preowned example represents discontinued production ending 2018 creating collectability. Blue crocodile leather strap with 18k white gold prong buckle completes presentation appealing to collectors valuing technical complications with unconventional display.