Complication · Calendar & astronomy
Age of the Moon
Partially verifiedA display showing the number of days elapsed since the last new moon.
Definition
A display showing the number of days elapsed since the last new moon.
Historical origin
A traditional astronomical indication often paired with a moon phase disc.
How it works
A scale from 1 to 29.5 days is printed on the dial, with a hand or a pointer showing the current day in the lunar cycle.
Pocket watch context
Common on eighteenth and nineteenth-century clocks and fine pocket watches.
Wristwatch context
Found in high-end calendar wristwatches.
Identification
- A scale numbered up to 29 1/2
- Often located around the moon phase window
Servicing notes
Must be adjusted alongside the moon phase.
General guidance only. Complicated mechanisms should be assessed and serviced by a qualified watchmaker or clockmaker specialist, not adjusted at home.
Related photographs
No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.
Sources & references
- de Carle, D., Watch and Clock Encyclopedia
- Britten, F. J., Old Clocks and Watches and Their Makers
- Horological Journal (British Horological Institute), technical articles
Where sources disagree, the disagreement is stated rather than resolved silently.