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The Encyclopedia of Horology

Wristwatch · Calendar wristwatch

Omega Cosmic Calendar Wristwatch

Partially verified

This vintage Omega Cosmic wristwatch, reference OT 2473, was produced on July 8, 1948, and subsequently delivered to Switzerland. Housed in a 34 mm 18-karat gold case, the watch features a manual-winding movement, specifically the calibre 27 DL PC, identified by movement number 10933104. The watch includes a calendar complication displaying the day, date, and month, alongside a moon phase indicator. The dial is described as having a gilt finish with applied indices, alpha gold hands, and a blue date pointer. The watch is accompanied by an extract from the archives, an original box, and an original clasp. The auction description notes the case includes a push-back mechanism and is finished with rounded lugs. The watch is currently fitted with a leather strap. The condition is described by the auction house as very good, noting slight wear to the case and oxidation on the dial.

Front view of the Omega Cosmic 18K gold calendar wristwatch with moon phase and brown leather strap.
Front view of the Omega Cosmic 18K gold calendar wristwatch with moon phase and brown leather strap. — Invaluable. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.invaluable.com
Category
Wristwatch · Calendar wristwatch
Maker / attribution
Omega
Reference
OT 2473
Catalogue / lot identifier
343
Source-reported date
1948
Source-reported place
Switzerland
Source-reported serial
10801564

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial Design

The watch is housed in an 18-karat gold case measuring 34 mm in diameter. It features a chamfered bezel and rounded, integrated lugs. The case back is designed as a push-back closure. The auction house reports the case is in very good condition with slight wear.

The dial displays a gilt finish with applied indices and gold alpha hands. It integrates multiple complications, including day, month, and date indicators, and a moon phase display at the 6 o'clock position. The day and month are displayed via windows in German, while the date is indicated by a blue pointer. The auction description notes the dial has developed an even patina.

Evidence for this section
  • “The warm 18 carat gold case features a chamfered bezel with beautiful rounded lugs”
  • “Dial: Gilt, applied indexes, auxiliary seconds, German day-, date- and month indication, alpha gold hands.”

Movement and Functionality

The Omega Cosmic is powered by a manual-winding movement, recorded as calibre 27 DL PC, which was superseded by calibre 381 after 1949. The movement is identified by the serial number 10933104.

The auction house lists the movement's condition as very good and states it is capable of running, although they recommend a professional cleaning. The complexity of the movement allows for the simultaneous display of calendar functions and moon phase tracking.

Evidence for this section
  • “Movm.: Manual.”
  • “The elegance continues inside with an attractive pink gold movement and calibre 27DLPC”
  • “Movm.: very good, capable of running, cleaning recommended.”

Provenance and Documentation

The watch is accompanied by an extract from the Omega archives, which confirms its production date of July 8, 1948, and its destination market of Switzerland.

Included in the lot are the original box and the original clasp. The auction house notes that the gold hallmarks on the case are clearly visible, confirming the material composition.

Evidence for this section
  • “procuced on July 8, 1948 and delivered to Switzerland”
  • “Original box, Extract from the archives, original clasp”

Open research questions

  • What is the specific history of the '27 DL PC' movement in the development of Omega's calendar watches?
  • To what extent does the documented 'even patina' affect the legibility of the gilt dial markers?

Source evidence

Recorded claims and source quotations for Omega Cosmic Calendar Wristwatch
FieldSource-reported valueSource quotation
MakerOmega“Omega - Cosmic”
Case Material18 K gold“Case: 18 K gold, push back.”
ReferenceOT 2473“Ref. OT 2473”
Movement Caliber27 DL PC“Cal. 27 DL PC”
Production DateJuly 8, 1948“procuced on July 8, 1948”
Case Serial10801564“Case No. 10801564”
Movement Serial10933104“Movm. No. 10933104”

Visible details

  • Blue pointer hand for calendar date
  • German language day and month windows
  • Moon phase display at the 6 o'clock position
  • Rounded lugs integrated into the gold case

Research qualifications

  • The auction description states the movement is 'capable of running' but recommends cleaning.
  • The dial shows signs of oxidation and even patina, which is common for watches of this age.

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Omega - Cosmic

Reviewed 2026-10-26 · Record 330c5ccb3f

Terms in this record

Glossary explanations for terms named in this object’s record.

Other calendar wristwatch records