Japanese Era Years Explained: Reiwa, Heisei and Showa to AD

How Japanese era years work

Japan uses the Gregorian calendar for months and days, but alongside the Western year it also counts years by era names, called gengo. Since the late 19th century a new era has begun with each new emperor. The current era, Reiwa, began on May 1, 2019.

Each era counts its years from one. The first year is often written as gannen, meaning the original or first year, rather than as year 1. So 2019 was Reiwa gannen, 2020 was Reiwa 2, and today, October 23, 2026, is Reiwa 8.

Western dates are widely used in Japan, but era years remain common in official and traditional settings. You will see them on forms at municipal offices, on certificates, in some bank and insurance paperwork, on documents from schools, and in many contracts and invoices. Older records often use era years exclusively.

The conversion formulas

Converting is a matter of adding or subtracting a fixed number: the Western year just before each era's first year. Reiwa began in 2019, so Reiwa year = Western year - 2018, and Western year = Reiwa year + 2018. Reiwa 8 is 2026; 2030 will be Reiwa 12.

The same pattern works for the earlier modern eras. You will meet Heisei and Showa constantly, since they cover the birth dates of nearly everyone alive today. Taisho and Meiji appear mainly in older family and property records.

• Reiwa (R): from May 1, 2019. Western year - 2018.
• Heisei (H): January 8, 1989 to April 30, 2019. Western year - 1988.
• Showa (S): December 25, 1926 to January 7, 1989. Western year - 1925.
• Taisho (T): July 30, 1912 to December 24, 1926. Western year - 1911.
• Meiji (M): 1868 to July 29, 1912. Western year - 1867.

Watch out for transition years

Eras change on a specific date, not on January 1, so each transition year belongs to two eras. In 2019, January 1 to April 30 was Heisei 31 and May 1 onward was Reiwa 1. In 1989, January 1 to January 7 was Showa 64 and January 8 onward was Heisei 1, which means Showa 64 lasted only seven days. Likewise, 1926 was Taisho 15 until December 24 and Showa 1 for its last seven days, and 1912 was Meiji 45 until July 29 and Taisho 1 from July 30. (The 1912 and 1926 changes took effect on the day the emperor died, so some references also list that day as the last day of the old era; this guide treats it as the first day of the new one.)

This is the most common conversion error. Knowing that someone was born in 1989 is not enough to write the era year: a birthday on January 5, 1989 is Showa 64, while a birthday on March 1, 1989 is Heisei 1. Always check the full date when you convert a transition year.

A related point concerns the very early Meiji period. Japan switched from its traditional lunisolar calendar to the Gregorian calendar on January 1, 1873 (Meiji 6). Month and day values in documents from before that switch follow the old calendar and do not line up with Western dates.

Shortcuts for quick mental conversion

Using the last two digits of the Western year makes most conversions easy. For Reiwa, subtract 18: 2026 gives 26 - 18 = 8, so Reiwa 8. To go back, add 18 to the Reiwa year to get the last two digits.

For Heisei years from 2000 on, add 12 to the last two digits: 2005 is 5 + 12 = Heisei 17. For the 1990s, subtract 88: 1995 is 95 - 88 = Heisei 7. For Showa, subtract 25: 1964 is 64 - 25 = Showa 39, and 1985 is Showa 60.

Here is a full example. A person born on March 15, 1990 writes their birth date as Heisei 2, March 15, which appears on Japanese paperwork as 平成2年3月15日 or H2.3.15. A person born on November 2, 1985 writes Showa 60, November 2, or S60.11.2.

• Reiwa: last two digits - 18 (2026 is Reiwa 8)
• Heisei: last two digits + 12 for 2000 to 2018; last two digits - 88 for 1989 to 1999
• Showa: last two digits - 25 (1964 is Showa 39)

Filling in Japanese forms

Japanese forms usually show dates in the order year, month, day. Many birth date fields print the era names, often as the kanji 明治, 大正, 昭和, 平成 and 令和 or as the letters M, T, S, H and R, and ask you to circle one before writing the year, month and day. A field marked 年 is the year, 月 the month and 日 the day.

For the first year of an era, you will see both gannen (元年) and the numeral 1. If the form includes a filled-in example, follow its style. Some forms let you choose between Western and era years; whichever you pick, use it consistently on the same document so the reader does not have to guess.

Do not confuse a calendar year with the Japanese fiscal year, nendo, which government offices, schools and many companies run from April 1 to March 31. Reiwa 8 nendo runs from April 1, 2026 to March 31, 2027, so a document dated February 2027 can correctly refer to Reiwa 8 nendo even though the calendar year is Reiwa 9.

Forms also frequently ask for your age, meaning your completed years as of the date you fill in the form or another stated reference date. You may also hear of kazoe age, a traditional count in which a person is one at birth and gains a year every New Year's Day. It still appears in some customs, but official forms use completed years.

Checking with the age calculator

Once you have your birth date in Western form, the age calculator gives your age in completed years on any reference date, along with the number of days since birth and the days until your next birthday. It also shows the kazoe age mentioned above. For example, someone born on March 15, 1990 (Heisei 2) is 36 on October 23, 2026.

If a form asks for your age as of a particular date, such as the application date or the first day of the fiscal year, enter that date as the reference date rather than relying on today's age, since the answer changes on your birthday.