Patek Philippe 3940G Perpetual Calendar White Gold, circa 2006 – A Rare and Important Reference

This is the Patek Philippe Reference 3940G, a white gold perpetual calendar that holds a special place in the brand’s history. First introduced in 1985, the Ref 3940 marked a new era for Patek Philippe, featuring the ultra-thin automatic Caliber 240 Q movement. It was one of the first perpetual calendars made as a regular production model, helping to re-establish high-end mechanical watchmaking during a time of major threat to the traditional watch industry from Quartz models. The white gold version is among the rarest and more sought-after variants of the reference. The case measures 36mm, offering classic proportions, while the clean, well-balanced silver dial shows day, date, month, leap year, and moonphase in a clear and elegant layout. The Ref 3940 is known to be a favorite of Philippe Stern, Patek’s former president, which adds to its importance in the brand’s story. Today, it is seen as a landmark model—appreciated for its design, technical quality, and quiet presence on the wri