Japanese Era Names and Western Years
Japanese forms, contracts and official letters often write the year by era name: 令和8年 rather than 2026. Converting is simple arithmetic most of the time, but the eras change on a fixed day rather than on 1 January, and dates before 1873 belong to another calendar. This guide explains the rules behind the converter.
What an Era Name Is
Japan has counted years by era names (元号, gengō) for centuries. The way of writing a date with an era name is called 和暦 (wareki), "the Japanese calendar", although the months and days are the same as in the Western calendar. Since the Meiji era each emperor's reign has had a single era name.
Today the Era Name Act (元号法) of 1979 says two things: an era name is set by cabinet order, and it is changed only when a new emperor succeeds to the throne. Heisei and Reiwa were both set this way, each by a cabinet order called 元号を改める政令.
The Five Modern Eras
Each era runs from the day its name took effect to the day before the next era began. To convert a year, subtract the number in the last column from the Western year, or add it to the era year.
| Era | First day | Last day | Last year of the era | Western year − era year |
|---|---|---|---|---|
| Meiji 明治 | 1868 (see below) | 29 July 1912 | Meiji 45 | 1867 |
| Taisho 大正 | 30 July 1912 | 24 December 1926 | Taisho 15 | 1911 |
| Showa 昭和 | 25 December 1926 | 7 January 1989 | Showa 64 | 1925 |
| Heisei 平成 | 8 January 1989 | 30 April 2019 | Heisei 31 | 1988 |
| Reiwa 令和 | 1 May 2019 | – | – | 2018 |
The Taisho and Showa dates come from the imperial edicts kept by the National Archives of Japan; Heisei and Reiwa from the cabinet orders on e-Gov. The Heisei order was promulgated on 7 January 1989 and took effect the next day; the Reiwa order took effect on the day after the abdication of 30 April 2019.
Why One Year Can Have Two Era Names
Because an era begins on a fixed day, the year in which it changes is split between two names:
- 1912: Meiji 45 until 29 July, Taisho 1 from 30 July.
- 1926: Taisho 15 until 24 December, Showa 1 from 25 December, so Showa 1 lasted one week.
- 1989: Showa 64 from 1 to 7 January, Heisei 1 from 8 January.
- 2019: Heisei 31 until 30 April, Reiwa 1 from 1 May.
Dates that look plausible can therefore be impossible. 平成31年5月1日 never existed, because 1 May 2019 was already 令和元年5月1日, and 昭和64年1月8日 never existed either. When the converter receives such a date it says when the era ended and gives the right name of that day.
元年: The First Year
The first year of an era is usually written 元年 (gannen, "origin year"): 令和元年 is the same year as 令和1年. Both forms are understood, and official forms accept either. Some forms leave a box for the year number only; writing 1 there is correct.
Dates Before 1873
Japan adopted the Gregorian calendar by the calendar reform edict of Meiji 5 (改暦ノ布告): the day that would have been 明治5年12月3日 became 明治6年1月1日, which is 1 January 1873. Until then months and days followed a lunisolar calendar, so a date such as 明治3年5月5日 does not fall on 5 May 1870, and the converter gives only the year for Meiji 1 to 5.
The Meiji era name was proclaimed in the autumn of 1868 and applied to the whole year, so 明治元年 corresponds to 1868. Dates before that are in the Edo period and outside the converter's range.
Converting by Hand
- Western → era: find the era from the table, then subtract. 2026 − 2018 = Reiwa 8; 1995 − 1988 = Heisei 7; 1970 − 1925 = Showa 45.
- Era → Western: add the same number. Showa 50 + 1925 = 1975; Heisei 20 + 1988 = 2008.
- In 1912, 1926, 1989 and 2019, check the day as well as the year.
- When filling in a Japanese form, use the calendar the form asks for and keep it the same throughout the form.
Age Charts and the Zodiac Year
Japanese age charts (年齢早見表) list each year of birth with its era year, its sexagenary sign (干支, eto) and the age reached in the current year. The converter builds such a chart for every year since 1912. The 干支 combines ten heavenly stems and twelve earthly branches into a 60-year cycle: 1984 and 2044 are both 甲子, and 2026 is 丙午 (hinoe-uma). Age charts follow the Western year, while almanacs and fortune-telling often start the year at 立春, around 4 February.
Frequently Asked Questions
What year is Reiwa 1?
Reiwa 1 is 2019 from 1 May. From 1 January to 30 April 2019 the year was still Heisei 31.
How many years did Showa last?
Showa ran from 25 December 1926 to 7 January 1989, so its year numbers go from 1 to 64, although Showa 1 and Showa 64 were each only about a week long.
Do Japanese people still use era names?
Yes. Many government forms and certificates use era years, and the Western year is common as well. Forms usually say which one to use.
When will the era after Reiwa begin?
Under the Era Name Act the era changes only when a new emperor succeeds to the throne, and the new name is set by cabinet order. The converter will add the next era once it has been announced.
Sources
Source: e-Gov 法令検索: 元号法（昭和五十四年法律第四十三号） · Last checked:
Source: e-Gov 法令検索: 元号を改める政令（昭和六十四年政令第一号） · Last checked:
Source: e-Gov 法令検索: 元号を改める政令（平成三十一年政令第百四十三号） · Last checked:
Source: 国立公文書館: 大正十五年十二月二十五日以後ヲ改メテ昭和元年ト為ス・御署名原本・大正十五年・詔書一二月二五日 · Last checked:
Source: 国立公文書館: 明治四十五年七月三十日以後ヲ改メテ大正元年ト為ス・御署名原本・明治四十五年・詔書七月三十日 · Last checked:
Source: 国立公文書館: 今後年号ハ御一代一号ニ定メ慶応四年ヲ改テ明治元年ト為スノ詔 · Last checked:
Source: e-Gov 法令検索: 明治五年太政官布告第三百三十七号（改暦ノ布告） · Last checked: