JAEN

Japanese Era Converter

Convert between the Western (Gregorian) calendar and the Japanese era calendar (Meiji, Taisho, Showa, Heisei, Reiwa) in both directions. Automatically detects invalid dates that fall outside an era's actual range.

Input data is processed in your browser
Data is never sent to a server

Tool

Japanese Era DateReiwa 8, 7/17
R8.7.17
Era Reference Table
EraPeriodEra Years
Reiwa(R)2019-05-01 – PresentYear 1 – 8
Heisei(H)1989-01-08 – 2019-04-30Year 1 – 31
Showa(S)1926-12-25 – 1989-01-07Year 1 – 64
Taisho(T)1912-07-30 – 1926-12-24Year 1 – 15
Meiji(M)1868-01-25 – 1912-07-29Year 1 – 45

What is the Japanese Era Converter?

Government paperwork, contracts, and official forms in Japan still frequently use era-based (wareki) dates rather than the Western calendar. This free tool converts a Western date into its Japanese-era equivalent, or an era-based date into the Western calendar, with one click.

It supports the five modern eras — Meiji, Taisho, Showa, Heisei, and Reiwa — and automatically detects dates that don’t actually exist because they fall on the wrong side of an era transition (for example, “Showa 64, January 10”), a mistake that’s easy to make with manual calculation.

How to Use

  1. On the "Western → Era" tab, enter a date to see the corresponding Japanese era, era year, month, and day.
  2. On the "Era → Western" tab, select an era and enter the year, month, and day to see the corresponding Western date.
  3. Use the "Copy" button below the result to copy it directly.
  4. Open "Era Reference Table" to check the start date of each era.

FAQ

What happens if I enter a Japanese-era date that doesn't actually exist, like Showa 64, January 10?

Showa ended on January 7, 1989, and Heisei began the next day. "Showa 64, January 10" therefore never existed. This tool automatically detects such invalid combinations and shows an error message instead of a wrong result.

Does this support eras before Meiji (such as Ansei or Keio)?

No. Pre-Meiji era names are rarely used in practice today, so this tool only supports the five modern eras from Meiji (1868) onward — Meiji, Taisho, Showa, Heisei, and Reiwa.

How is the first year of an era (Gannen) displayed?

When converting from the Western calendar, the first year of an era is shown as "Gannen" (e.g. "Reiwa 1 (Gannen)"). When converting from the era calendar, entering "1" as the year is treated as Gannen.

Is my input or the result sent to a server?

No. All conversion happens entirely in your browser using JavaScript — nothing is sent anywhere.

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