HOW TO IDENTIFY SEIKO PRODUCTION DATE

How to the serial number works

Every Seiko watch manufactured is given a 6-digit serial number. There are however exceptions to this rule. Seiko watches made prior to the late 1960s, most probably 1967 have 7-digit serial numbers instead. Limited edition models with unique sequenced numbering, e.g. 123/300 (denoting the 123rd piece out of a total of 300 pieces) usually don’t have serial numbers.

Limited edition Seikos are usually made within a very short time frame – perhaps not more than a few months in the year it was introduced. In this case you’ll need to know the intimate history of the model – for example, the SBDX005 Historical Collection 600m diver was released in 2000 with 1,000 pieces made. You may not know the exact month the watch was made but suffice to say, the production year couldn’t be any later or earlier than 2000.

To simplify things, I will use the 6-digit serial number convention. This table below describes the structure of the serial number.

Digit Position	Description	Characters used	Notes
1	Production year	0 to 9	Denotes the year in the decade, not absolute year
2	Production month	1 to 9, "0", "N" and "D"	1 to 9 denotes months of January to October. "0", "N" and"D" denotes October, November and December respectively
3	Sequence number, thousands	0 to 9	The last four digits represent the running number of the watch
4	Sequence number, hundreds	0 to 9
5	Sequence number, tens	0 to 9
6	Sequence number, ones	0 to 9

Deciphering the serial number

• The first digit signifies the year the watch was made. It doesn’t tell you the decade – only the year. This will present a problem because you may not be able to distinguish whether the watch was made in 1997 or 2007. The digits always range from 0 to 9.
• The second digit denotes the production month. Seiko uses 1-9 for January to September. October is represented by the number 0 (zero, not the letter "O") while November and December are abbreviated to "N" and "D" respectively.
• The remaining 4 digits represent the production number of the watch in a sequence. It is generally believed that the first watch produced every month begins with "0000" and the last watch made in that month ends with "9999". Going by this convention, up to 10,000 watches of a particular model could be manufactured in one month. The sequence number is reset for the following month. Therefore if Seiko made up to 4,900 pieces in February, the last watch produced will have the the sequence number 4900. For the following month of March, the first watch produced will have the sequence number 0000 instead of 4901.

The following table below gives examples on how the serial numbers are interpreted:

Caliber	Serial Number	Year	Month	Watch Number
7S26A	717872	1997	January	7872
7T32	8N1030	1998	November	1030
6105	200421	1972	October	421
6138	731999	1977	March	1999
6309	4D8001	1984	December	8001
8L35	259393	2002	May	9393
7S26B	760023	2007	June	23

FROM THE TABLE SHOWN YOU CAN IDENTIFY THIS SEIKO CHRONOGRAPH PEPSI BEZEL MODEL 6319-8002 AND SERIAL NUMBER 223399, THE YEAR MANUFACTURED WAS FEBRUARY 1972

NOW, YOU CAN EASILY IDENTIFY YOUR SEIKO PRODUCTION DATE BY CHECK THE TABLE IN THIS BLOG. SELAMAT MENGIRA....