32. 32Y Patek Philippe. A fine 18K gold automatic perpetual calendar wristwatch with moon phase and sigma dial Model: Perpetual Calendar Reference: 3940 Date: Purchased 22nd November 1999 Movement: 27-jewel Cal.240Q automatic, adjusted to heat, cold, isochronism and 5 positions, stamped with the Seal of Geneva, Gyromax balance, 22K gold micro-rotor, No.774114 Dial: Silvered 'sigma', applied 18K gold pointed baton hour markers, dot outer minute markers, subsidiary dials at 3, 6 and 9 indicating day combined with 24-hour display, month combined with leap year indication, and phases of the moon combined with date, 18K gold dagger hands Case: Brushed and polished round, solid snap on back, quick set buttons in the band at 6, 9 and 12, No.2936250 Strap/Bracelet: Patek Philippe black crocodile leather Buckle/Clasp: Signed 18K gold buckle Signed: Case, dial & movement Size: 36mm Weight: 59,90g Accompaniments: Patek Philippe box, outer card, Certificate of Origin, Original invoice, spare 18K gold exhibition snap on back In 1984 Patek Philippe launched the reference 3940, to replace the reference 3450. At the time, it was their slimmest automatic perpetual calendar. In the first year of production only 100 examples were manufactured but by 1985, the model went into standard production. It was discontinued in 2007, and replaced by the reference 5140.