18ct white gold Patek Philippe ref. 3940 Perpetual Calendar wristwatch with moonphase. Made 2006

Information

• Brand: Patek Philippe
• Made: 2006
• Model: Perpetual moonphase 
• Reference: 3940
• Calibre: 240 Q
• Movement: Automatic
• Material: 18ct white gold 
• Features/complications: Perpetual calendar with moonphase 
• Dial: Opaline dial with applied 18ct white gold mirror polished beaded outer minute track and lapped hour indices, subsidiary seconds at 3 o'clock for month indicator, 6 o’clock for day of the month indicator with moonphase window and day of the week indicator at 9 o'clock with 9 o clock for the day of the week indicator with 18ct white gold Dauphine hour and minute hands
• Case dimensions: 36mm
• Bracelet/strap: Leather strap 
• Accessories: Spare solid caseback and pusher
• Additional information:  This watch dates from the fourth series
• SKU: 3312

Essay

Patek Philippe first launched the 3940 in 1985 to replace the existing perpetual calendar wristwatch. At the time of manufacture, it was amongst one of Patek Philippe's longest running references ever produced, ceasing production in 2007. The reference was cased predominantly in yellow gold, as well as pink gold, white gold, and platinum.

The 3940 is considered as undeniably the quintessential automatic perpetual calendar perpetual calendar reference manufactured by Patek Philippe. Powered by what was then the all-new, ultra-thin calibre 240, Patek Philippe’s first movement to use a micro-rotor, it enabled an elegant and very thin case that fit tightly to the wrist.

The reference 3940 was executed in three different series (and a very small “pre-series”):

First series (commonly known as the pre-series): 25 numbered pieces produced with a gilt dial to celebrate the 225th anniversary of the famed retailer Chronometrie Beyer in Zürich.

Second series: without second case back, sunken sub dials, 24-hour counter in two-tone.

Third series: with second back (all but platinum), sloped sub dials, 24-hour counter two-tone.

Fourth series: with second back (all but platinum), sloped sub dials, monochrome 24-hour counter.

Becoming increasingly collectible, the 3940 underwent several evolutions.