Hi
Many years ago, I have been told or read somewhere that in Japan, shinsakuto must be dated by law on their nakago.
Indeed during, years every shinsakuto I saw had a date of production engraved on their nakago.
Yesterday, I saw a shinsakuto by a top smith for sale on a well known Japanese seller website. The sword has no date engraved, only the mei.
Hence I asked the seller why no date and he replied the following : " I do not know from where you obtained such information, but while it is mandatory to engrave the name of the swordsmith, it is not legally required to engrave the date of production. Currently, there is a 50/50 split between those who engrave the date and time and those who do not."
If someone of the NMB has a documented answer about this, I would love to read it.
Thanks