Swiss 18K gold lever with linear calendar and moon phases Circa 1981

Gold open faced pocket watch by Patek Philippe
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A Swiss 18 carat gold open faced lever pocket watch with linear perpetual calendar and moon phases, circa 1981. Sold on November 20th, 1981. The lever movement with 18 jewels. Silvered dial with raised gold hour batons and Arabic 12, outer minute divisions, an aperture for displaying the months, date and days at 12 o’clock, subsidiary seconds with concentric moon phases at 6 and dauphine hands. The plain case with a snap-on back. Dial signed, case and movement signed. Comes with the original presentation box and an Extract from the Archives.
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Diameter: 48 mm
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Signed: Patek Philippe Genève Swiss
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The linear digital calendar or so-called American (perpetual) calendar is a calendar in which the date is displayed in a single linear aperture, allowing for a legible dial to be read at a glance. This type of display was invented in the early Art Deco period and is most often found in watches destined for the Anglo-American market. This kind of calendar became popular once again after the Second World War.