Seiko Serial Numbers with Production Dates and Movement Types

How is the Date Calculated

The first digit of the serial number tells you the last digit of the year the watch was made.

For many of Seiko’s movements we know the first year they were produced and for most movements they were produced for less than 10 years. This helps us narrow down the decade.

The second digit of the serial number is also useful. It tells you the month the watch was manufactured. Here are the possible values:

• 1 = January
  2 = February
  3 = March
  4 = April
  5 = May
  6 = June
  7 = July
  8 = August
  9 = September
  0 = October
  N = November
  D = December

The remaining four digits of the serial number indicate the production number for the watch. If your last for digits are 0000 then you have the first watch made for that model reference number.