How to date the production of your (Grand)Seiko? There is a serial-number stamped on each Seiko and it is build in the format YMXXXX. The first digit being the year of production and the second the month of production -- the decade of production could be derived from the caliber used. The following numbers are a running serial from this production-batch. So 980012 on a Seiko ref6145-8030 is the twelfth watch produced in August 1969 of this remarkable reference. The cal61 was produced in the late 1960s and early 1970s and so the 9 is for sure 1969.

It is obvious that this is quite a useful information and the transparency of Seiko on this (production-date & -quantity) is much bigger than most Swiss competitors.

Time goes on for GS and with the expanding to the world market and making it a standalone brand, even the former Japanese design is "very fine adjusted": while clear, subtle and "less is more" was a major design principle before we see verbose texting, oversized triple-indexes and strange fat hands on their new models (photo-source Grand-Seiko.com).