Seiko & Citizen Watch Forum Message Archive

Well,unfortunatly,from what I`ve heard here,Seiko is very conceling about such things as production quantitys,and perhaps even exact dates produced. We have a resident expert on such things (Ryan),maybe he can shed some light on the paticular movement.

As far as dating you specific watch,heres what Ive heard,and it has worked very well for me.

The first number of the ser number is the year it was produced. This wont tell you the decade it was made,so some prior knowlege about the decade the style was being produced is neccesary.

The second number or letter,is the month in that year it was made. Now,I know this is going to contradic whats been said lower on the board,but I think this is the correct sequence. The numbers 1 through 9 indicate january,though september. The letters "O","N" and "D" mean october,november,and december.

I have a Seiko on right now,let me use it as an example. My watches Ser.# is 539621. Because of its cal number (6309),Im confident it was made in the 70`s,so I belive this watch was made in March,of 1975.

If the Ser.# had been 5n9621,it would have been made in November,of 75.

So,I belive I can tell you that the 4205 was being made in the 80`s. When it stoped,I do not know. But this,and your serial number should tell you when your watch was produced.

If I`m wrong,someone please shed some light on this.

Cheers,Randall