Pocket watches · Complication
Calendar Pocket Watches
Partially verifiedWatches displaying the date, and often the day and month, in addition to the time, ranging from simple date apertures to full perpetual calendars.
Mechanism
A calendar wheel advanced once per 24 hours by a jumper acting on the motion works drives the date display; perpetual calendars add a program wheel that reads the length of each month over a four-year cycle.
Typical characteristics
- Date hand, aperture or subsidiary dial
- Additional day-of-week and month indications on more complex examples
- Perpetual mechanisms that account for varying month lengths and leap years
Identification characteristics
- Extra dial furniture for date, day or month
- Correction pushers set into the case band on perpetual examples
Collector significance
A widely produced complication ranging from simple and robust to among the most complex mechanisms made.
Known variations
- Simple date
- Triple calendar (day, date, month)
- Perpetual calendar
- Annual calendar
Photographs
Photographs are illustrative examples of the type, not necessarily the exact object described. Verify details against the source file page.
Sources & references
- General horological surveys
Where sources disagree, the disagreement is stated rather than resolved silently.