As of October 2010, Seiko launched the Grand Seiko in approximately 20 markets around the world. Representing the best of Seiko, in 1960 Seiko launched the first Grand Seiko, a luxury watch brand made for men, which continues to feature a broad range of technologies. You might be curious to learn when Seiko manufactured your watch, especially if you received one as a gift or if you own a very old Seiko watch. Calculating the manufacturing date can also help you if you want to sell your Seiko watch or if you want to get a true bargain when buying one.
Locate the serial number engraved on the back of your watch case, under the name "SEIKO." You will also find the model number and the movement number engraved on the back. The movement number represents the classification number of the working parts of your watch.
Interpret the first digit of the serial number as the manufacturing year. You would need to know the nearest decade to know the exact year. For instance, if "268451" represents the serial number for your Seiko watch, and you know the nearest decade Seiko made your watch was 1990, the first digit would represent the year 1992.
Translate the second digit of the serial number as the month Seiko produced your watch. This digit could be a number or a letter. For example, for the months of January through September, the second digit would be 1 through 9. The second digit would be the letters O, N and D, for the months of October, November and December. For the serial number "268451," your Seiko watch was manufactured in June 1992.