Modern 9-character serial
The first character gives the year ending. The second gives the month: 1–9, then 0 or O for October, N for November and D for December.
Free Citizen watch tool
Citizen serial number decoder
Estimate the production month and possible year using the serial era, movement and date code engraved on the watch.
Modern and pre-1980 modes
Estimate, not authentication
Production date estimator
Choose the serial era
Citizen used different date patterns. Select the correct era rather than letting the tool guess from length alone.
The calculation runs in your browser. Wrist Bear does not receive or store the serial number.
Method
How the Citizen modes differ
The tool keeps the two systems separate because an eight-digit number should not be assumed to be vintage without context.
Vintage 8-digit serial
For documented pre-1980 examples, the first digit gives the year ending and the next two numeric digits give the month from 01 to 12.
Known limitations
- The vintage convention is intended only for watches produced before 1980.
- Some model families need movement history or an approximate decade to resolve the repeated year digit.
- A case number is not automatically the same as the production serial.
- Service replacement parts can make a date estimate misleading.
Worked examples
Modern: 8O1123456 with F990 indicates October 2018.
Vintage: 31100039 with movement 8110 indicates November 1973.
Without movement or era context, the tool shows multiple possible years instead of selecting one silently.
Questions
Citizen serial number FAQ
Use the estimate together with the movement, model family, warranty papers and ownership history.
Why must I choose modern or vintage?
The date fields sit in different positions. Choosing the era prevents a plausible-looking but incorrect result.
Where do I find the movement number?
The first four characters of the case number on many Citizen casebacks identify the movement, although placement varies by model.
Can this confirm authenticity?
No. Citizen uses serial information for service and identification, but a date-shaped number alone cannot authenticate a watch.