Taishō (大正) gannen — 1912

The first year is not “1”, it is gannen

Japanese documents write the first year of an era as 元年 (gannen), not 1. It is 令和元年, never 令和1年. The value counts as one in arithmetic but is written differently, which is where transcriptions usually go wrong.

The same Western year

Meiji to Taishō and Taishō to Shōwa changed **on the same day**, so one calendar day belongs to both eras: 30 July 1912 is Meiji 45-07-30 and Taishō 1-07-30 at once. Shōwa to Heisei and Heisei to Reiwa changed **the next day**, so a single day separates them: Shōwa 64 ends on 7 January and Heisei 1 begins on the 8th.

Converting is one addition

Each era has a fixed number to add: 1867 for Meiji, 1911 for Taishō, 1925 for Shōwa, 1988 for Heisei, 2018 for Reiwa. Reiwa 6 is 6 + 2018 = 2024. The numbers differ not because the rule differs but because the eras began in different years — in every era, year one sits on the year it began.

The years either side

Other years of this era

The year of a change carries both names

1912 is Meiji 45 and Taishō 1; 1926 is Taishō 15 and Shōwa 1; 1989 is Shōwa 64 and Heisei 1; 2019 is Heisei 31 and Reiwa 1. In all four, neither label is wrong — only the date within the year decides which era applies.

How to read this

• Western year = era year + a fixed number (Meiji 1867, Taishō 1911, Shōwa 1925, Heisei 1988, Reiwa 2018).
• The first year is written 元年 (gannen), not 1.
• A year in which the era changed carries two era names; only the date settles it.
• Meiji and Taishō began on the same day as the previous era ended; Shōwa onward, the next day.