Since the early 1960's Seiko have used a date system within their serial number.
The first digit is the year made
The second digit is the month made
1 - Jan
2 - Feb
3 - Mar
4 - Apr
5 - May
6 - Jun
7 - Jul
8 - Aug
9 - Sep
O - Oct
N - Nov
D - Dec
The remaining digits are the serial number
The only thing you have to know is what decade the watch was made. The 7009A movement was one the most numerous, unfortunately the date calculator is not that good on this movement. From the information I can find I believe it was introduced in 1980 and was superseded by the 7S26 in the late 1980's, early 1990’s.
Movement:7009 Case:821A Serial No:8D7545
Year made 1988.
Month made December.
Hi Seikowatch and welcome hope you enjoy the site there's some great members with truly informative information...I'm also a Seiko lover but lately we all seemed to have bought Seiko 5's...anyhow I digress, welcome again.
Thats a very nice collection you have there Ian. I would find it difficult to explain to a non watch person what the fascination with watches was all about. Whatever it is you've got it and I don't think there is a cure.
RogerC
Hello & welcome to the forum. If you want to date your Seiko go here http://www.csce.uark.edu/~jgauch/photos/seiko/ it woks well. Seiko movement parts & crystals are quite easy to find, case parts less so. As for the dials, unless its a diver, chrono or bellmatic spares are very rare.
I love Rotary, there is something quintessentially British about them (even though they are Swiss!) Reliable and always, like this one, have some lovely designs. I bet you get a lot of pleasure out of that one!
I would love to get one day one of their vintage mechanical 9K gold models, just timeless design I feel.