When is it appropriate to begin referring to 明仁 as 平成天皇?


The upcoming abdication of the Chrysanthemum Throne, the enthronement of
[徳仁]{なるひと} and the start of the [令和]{れいわ}[時代]{じだい} presents a specific and
unusual conundrum:

It has become customary to refer to former (i.e. dead) emperors of Japan by
their era name rather than their given name, and impolite to refer to the
sitting emperor by their era name.

The question then: Is this custom tied to enthronement and abdication (making
[明仁]{あきひと} [平成]{へいせい}[天皇]{てんのう} on May 1st), or is it tied to 明仁's actual
death (date TBD)?




The current Emperor Akihito will be called **上皇【じょうこう】** ("Emperor Emeritus")
after the abdication on April 30. The full name with an honorific title will
be (明仁)上皇陛下 ("His Majesty the Emperor Emeritus (Akihito)"). Something like
昭和天皇 is a 追号 ([posthumous
name](https://en.wikipedia.org/wiki/Posthumous_name#Japan)), and the current
Emperor will not be called 平成天皇 until his demise. (To be precise, his 追号 [can
be different](https://twitter.com/Kakanien_Sazae/status/1110807521118150656)
from 平成天皇, but this is highly unlikely.)

References:

  * [Wikipedia - 上皇 (天皇退位特例法)](https://ja.wikipedia.org/wiki/%E4%B8%8A%E7%9A%87_\(%E5%A4%A9%E7%9A%87%E9%80%80%E4%BD%8D%E7%89%B9%E4%BE%8B%E6%B3%95\))

> 上皇（じょうこう、英: Emperor
> Emeritus）とは、2019年（令和元年）5月1日以降の、天皇の退位等に関する皇室典範特例法第二条の施行に基づき退位する日本の天皇の称号。

  * [nippon.com -- Emperor Akihito to Be Called Emperor Emeritus after Abdication](https://www.nippon.com/en/news/yjj2019022501074/emperor-akihito-to-be-called-emperor-emeritus-after-abdication.html)

> Emperor Akihito will be called the Emperor Emeritus and Empress Michiko the
> Empress Emerita after the Emperor's abdication on April 30, the Imperial
> Household Agency said Monday. It has been already decided that in Japanese
> the Emperor's post-abdication title will be Joko and the Empress' Jokogo.




The current Emperor Akihito will be called **上皇【じょうこう】** ("Emperor Emeritus")
after the abdication on April 30. The full name with an honorific title will
be (明仁)上皇陛下 ("His Majesty the Emperor Emeritus (Akihito)"). Something like
昭和天皇 is a 追号 ([posthumous
name](https://en.wikipedia.org/wiki/Posthumous_name#Japan)), and the current
Emperor will not be called 平成天皇 until his demise. (To be precise, his 追号 [can
be different](https://twitter.com/Kakanien_Sazae/status/1110807521118150656)
from 平成天皇, but this is highly unlikely.)

References:

  * [Wikipedia - 上皇 (天皇退位特例法)](https://ja.wikipedia.org/wiki/%E4%B8%8A%E7%9A%87_\(%E5%A4%A9%E7%9A%87%E9%80%80%E4%BD%8D%E7%89%B9%E4%BE%8B%E6%B3%95\))

> 上皇（じょうこう、英: Emperor
> Emeritus）とは、2019年（令和元年）5月1日以降の、天皇の退位等に関する皇室典範特例法第二条の施行に基づき退位する日本の天皇の称号。

  * [nippon.com -- Emperor Akihito to Be Called Emperor Emeritus after Abdication](https://www.nippon.com/en/news/yjj2019022501074/emperor-akihito-to-be-called-emperor-emeritus-after-abdication.html)

> Emperor Akihito will be called the Emperor Emeritus and Empress Michiko the
> Empress Emerita after the Emperor's abdication on April 30, the Imperial
> Household Agency said Monday. It has been already decided that in Japanese
> the Emperor's post-abdication title will be Joko and the Empress' Jokogo.

