"mr.sumo.snr." wrote:

> Simple question.  Why does Japan celebrate the end the year on December
> 31st?  I'm fully aware that the Gregorian calendar was introduced 1873.  And
> am therefore guessing that it had something to do with the Meiji era
> social-political reforms.  But if anyone has anything more detailed I'd be
> grateful.

The 3rd day of the 12th month of 1872 became January 1 1873.  This change was
announced only one month in advance, on the 9th day of the 11th month.

According to the lunar calendar used during the Tokugawa era, one year had 254
days, or eleven days less than the solar calendar now in use.  Under this old
system it was necessary to add seven leap months every nineteen years.  This
meant extra paydays, which the financially starved government wanted to get rid
of.  By the lunar almanac 1873 was a year with an extra month.

Of course the major motive was putting their social system in sync with the
West.

Douso, The Prophet of the Way