Glossary · Mechanism
Calendar mechanism
Dial-train gearing that advances a date, day or month indication once every twenty-four hours.
Explanation
A calendar mechanism advances a date indication, usually by a finger or jumper acting on a 31-tooth date ring once a day, driven from the hour wheel. Simple calendars need manual correction after short months; annual and perpetual calendars add programs that account for month length. Forcing the date change near midnight, while the mechanism is engaged, is a classic way to damage it.
In the object catalogue
Catalogued objects whose own source record mentions “Calendar mechanism”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.
Wristwatch
Vacheron Constantin Traditionnelle Perpetual Calendar Skeleton, Ref. 43172/000P-9236
“The Vacheron Constantin Traditionnelle Perpetual Calendar Skeleton, reference 43172/000P-9236, is a platinum wristwatch reported by the source as manufactured in 2007. The 39mm …”
Clock
Carriage Clock by Wurtel
“This ornate gilt carriage clock is attributed to Wurtel and dated to circa 1845 in Paris, France. Preserved in the Science Museum Group collection, the clock is housed in an ela…”
Wristwatch
Vacheron & Constantin Ref. 43031 Perpetual Calendar Wristwatch
“This Vacheron & Constantin gentleman's wristwatch, reference 43031, dates to the 1980s. The watch features a massive platinum case measuring 36 mm in diameter, characterized by …”
Wristwatch
Patek Philippe Gondolo Annual Calendar Ref. 5135G
“This Patek Philippe Gondolo Annual Calendar, reference 5135G, is an 18K white gold wristwatch manufactured in 2006. The watch features a tonneau-shaped case measuring 38 x 51 mm…”
Pocket watch
Swiss Double Dial Calendar Pocket Watch
“This Swiss keyless pocket watch, numbered 6288, dates to approximately 1900. Housed in an 18K pink gold three-body bassine hunting case, it features champlevé guilloché enamel d…”
Pocket watch
Patek Philippe Astronomical Keyless Pocket Watch
“This Patek Philippe & Cie. keyless pocket watch, numbered 48280 and manufactured in 1878, was sold to A. Maurer on 3 March 1884. It is constructed in an 18K pink gold 'bassine' …”