Japanese Dates and the Japanese Calendar (Nengo)

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The Gregorian calendar has been used in Japan since 1 January 1873, but dates are typically written in the format, "Year Month Date" similar to the style "2004-02-25" which of course corresponds to February 25, 2004.  In actual Japanese characters, this would be written as "2003年2月25日".   Japanese always uses this order, and always uses numbers to represent the month and date.

But Japan also uses a traditional naming scheme for years called Nengo.  It is based on a two kanji character name corresponding to the reigning emperor.  Since the ascension of the Meiji Emperor and now under current Japanese law since 1979, this era name changes only when a new emperor comes to power.  That entire calendar year is then referred to as "1" and is incremented by one corresponding to each western calendar year, on January 1.  Once deceased, the respective emperor will thereafter be referred to as the name of the corresponding era when he held power.

The previously given date would be written using Nengo by adding the name of the era before the year number, i.e.Heisei 16, as in 平成16年2月25日".   When using roman script for writing, the era name, in this case Heisei, is also often abbreviated with a single character as in H15.  (S is for Showa, T is for Taisho and M is for Meiji.  There are others before this, but these are the only years anyone normally sees any more.)

The Nengo date format is usually required for government document and for corporate documents. It can be seen on the Family Register, the Residency Registration and any other document from a local government office.

The following is a list of the most recent four era names and the corresponding emperor name, while he was alive.

Here is a list of the years in each era and the corresponding western (Gregorian) calendar year.  (Note that the final year of any era is not normally used, since it was not a full year. In the case of Showa, it was only several days long.)