The certificate mentioned that this watch was sold on July 23, 2001. Patek Philippe, Reference 5050 Production of this reference started in 1993 (with the yellow gold version only) and remained in production until circa 2001-2002. In 1995, Patek Philippe offered the full range for sale: yellow gold, white gold, pink gold and platinum. Only one dial colour - opaline grey - was available for the four different metals, but it was possible to choose between indexes or Roman numerals. However, only around 30 examples were made in pink gold, white gold and platinum with Roman numeral dials. This model was the first Patek Philippe perpetual calendar wristwatch to feature a "retrograde" date. In 1993-1995 when the reference was first shown, this complication went largely unnoticed. It was only when the watch was discontinued in 2001-2002 that it became a sought-after complication, by then widely used by other brands. This type of perpetual calendar with retrograde date was subsequently used on the well-known minute repeater, Ref. 5016. With the day and month visible in an aperture (small window), as well as the leap year indication, it was the successor to Ref. 3450, and like 3450, was produced in very small quantities.