Japanese Era Converter (Wareki)

How do I convert a date to the Japanese era (wareki)?

Pick the Western date and this tool finds which of the five modern eras (Meiji, Taisho, Showa, Heisei, Reiwa) it falls in, then subtracts the era's start year and adds one to get the era year — the first year of any era is written gannen (元年) rather than “year 1.”

Switch the mode to go the other way: pick an era and a year number (or gannen) to see the matching Western year, useful for reading old documents, gravestones, or koseki records.

How do I convert a Western date to the Japanese era (wareki)?

Find which of the five modern eras the date falls in by comparing it to each era's start date, then subtract the era's start year from the date's year and add one. Example: 2024-03-15 falls after Reiwa's start (2019-05-01), so its era year is 2024 - 2019 + 1 = 6, written Reiwa 6 (令和6年).

Steps to find the era year

1. List the start dates of the five modern eras: Meiji 1868-01-25, Taisho 1912-07-30, Showa 1926-12-25, Heisei 1989-01-08, Reiwa 2019-05-01.
2. Compare your date to each start date and keep the latest era whose start date is on or before your date.
3. Subtract that era's start year from your date's calendar year, then add 1 to get the era year.
4. If the result is 1, write it as gannen (元年) instead of "year 1" — this is the standard convention for the first year of any era.
5. For transition years (1912, 1926, 1989, 2019), check the month and day carefully since the same calendar year splits between two eras.

The era-year formula

• Era start year = the Gregorian year in which that era's start date falls (Meiji 1868, Taisho 1912, Showa 1926, Heisei 1989, Reiwa 2019)
• Gannen (元年) = the label used instead of "year 1" for the first year of any era

Example conversions

Frequently asked questions

Why is 1868 the starting point for this converter?

The Meiji era is the first of Japan's modern eras under the current one-era-per-reign system (一世一元の制). Earlier eras (Keio, Genji, and so on) used a different, more irregular system with multiple era changes per reign, which this tool does not cover.

What does gannen (元年) mean and why isn't it just "year 1"?

Gannen literally means "origin year" and is the standard Japanese term for the first year of any era, used in place of "1年." You will see it on official documents, coins, and newspapers dated in the year an era begins — for example 令和元年 for 2019, the year Reiwa started.

Why do 1989 and 2019 have two possible era years?

Both years contain an era transition partway through. 1989 is Showa 64 for the first seven days (through January 7) and Heisei 1 (gannen) from January 8 onward. Similarly, 2019 is Heisei 31 through April 30 and Reiwa 1 (gannen) from May 1 onward — the exact month and day determines which applies.

Is there an upper limit to how far into Reiwa this tool can convert?

No. Reiwa is the current era with no announced end date, so this tool calculates any future Reiwa year the same way as any other year, simply by adding 1 to the difference from 2019.

This tool covers the five modern Japanese eras from Meiji (1868-01-25) onward using the one-era-per-reign system; it does not cover pre-Meiji era names, and era start dates are calendar dates, not the exact hour of transition.

Sources: Wikipedia — 元号一覧 (日本)