Glossary · Complication
Perpetual calendar
A calendar complication that automatically accounts for month lengths and leap years.
Explanation
A perpetual calendar automatically accounts for the different lengths of months and for leap years, needing no correction until 2100 (a skipped leap year under the Gregorian rule). A mechanical program — traditionally a 48-month cam — encodes the calendar cycle. First made in pocket watches in the 18th–19th centuries (Thomas Mudge made an early example in 1762), it is among the most prestigious complications.
In the object catalogue
Catalogued objects whose own source record mentions “Perpetual calendar”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.
Pocket watch
Usher & Cole Minute Repeating Perpetual Calendar Pocket Watch
“Usher & Cole Minute Repeating Perpetual Calendar Pocket Watch”
Pocket watch
Paul Ditisheim Astronomical Precision Pocket Watch No. 13784
“This astronomical precision pocket watch by Paul Ditisheim features a 61mm 18ct yellow gold Empire case with a reeded band. The white enamel multi-piece dial displays Arabic num…”
Wristwatch
A. Lange & Söhne Ref. 310.025 Langematik Perpetual
“This A. Lange & Söhne Langematik Perpetual, reference 310.025, is a self-winding perpetual calendar wristwatch in a platinum case measuring 38.5 mm in diameter. According to the…”
Pocket watch
Breguet yellow gold perpetual calendar openface pocket watch
“Breguet yellow gold perpetual calendar openface pocket watch”
Wristwatch
Audemars Piguet Ref. 26574OR.OO.1220OR.03 Royal Oak Perpetual Calendar
“Audemars Piguet Ref. 26574OR.OO.1220OR.03 Royal Oak Perpetual Calendar”
Wristwatch
Breguet Marine Tourbillon Équation Marchante, Reference 5887PT/Y2/9WV
“This Breguet Marine Tourbillon Équation Marchante is a platinum perpetual calendar tourbillon wristwatch dating to circa 2022. It features a blue wave-pattern guilloché dial wit…”