A. Lange & Söhne Ref. 310.021 FE, self-winding, bissextile perpetual calendar with “Grande Date”, moon phases, AM-PM indication; “Langematik Perpetual”; 18K yellow gold | Important Modern & Vintage Timepieces | Monaco, July 21, 2021
A. Lange & SöhneRef. 310.021 FE, self-winding, bissextile perpetual calendar with “Grande Date”, moon phases, AM-PM indication; “Langematik Perpetual”; 18K yellow gold, 18K yellow gold, self-winding, round-shaped, gentleman’s wristwatch, water-resistant with sapphire-crystal case-back screwed by six screws, silver colour dial with applied 18K yellow gold radial Roman numerals and seven horological complications:• Half-instantaneous perpetual calendar• Grande Date of the month (double aperture at 12 o’clock)• Day of the week (subsidiary dial at 9 o’clock; indications given in English)• Month of the year (subsidiary dial at 6 o’clock; indications given in English)• Four-year cycle of leap-years (subsidiary dial at 4 o’clock)• Phases of the moon (subsidiary dial at 6 o’clock)• Diurnal (day-time) and nocturnal (night-time) indication (subsidiary dial at 9 o’clock)
