However, Platinum nibs are stamped with a date code, thus providing a very solid starting point to that typical approach. The dating code is, more often than not, printed on the reverse of the nib, and there is a catch—for most of its history, Platinum nib dates were referred to the Japanese calendar, based on the years of reign of the emperor. Fortunately –for our dating purposes, that is—emperor Hirohito had a long life that eliminated most ambiguities this dating system could have created. But at some point between 1989 and 2000 –either at the change of emperor between the Showa and the Heisei periods, or at the change of millennium—Platinum adopted the Western calendar.
On the left, a music nib dated on December of 2009. On the right, a one-slit nib made on September of 2009. These modern nibs are dated following the Western calendar.
The converse sides of the previous nibs. They belong to a modern 3776 model with a music nib, and to a Nakaya with a soft fine nib.
The dating code follows a simple pattern. It has the form
where aa is the month of the year BB. The figure aa is often one single digit. Needless to say, year 10 in the Japanese calendar could either mean 1922 (Taisho year 10), 1936 (Showa year 10) or, eventually, 1999 (Heisei year 10). This ambiguity is easy to resolve.
This datation system works as long as the nib had not been replaced.