Japanese Era Converter

How to use

1. To start from a Western year, type it into "Western year" under "Western year to Japanese era". The month and day are optional. "Today" fills in today's date
2. To start from an era, pick the era under "Japanese era to Western year" and type the era year. The first year can be entered as 1 or as 元
3. The era date, the Western date, the short form (such as R8) and the zodiac appear as you type. With a full date, the weekday appears as well
4. Below the result, a small table lists the three years before and after
5. "Copy" copies the converted result
6. To convert a column of dates from a list or spreadsheet, paste them into "Convert a list", one per line. Era dates and Western dates can be mixed

Full-width digits are accepted as they are. The dates you enter are never sent out of your browser and are not stored.

Example

Typing 1990 into "Western year" shows:

• Japanese era: Heisei 2 (平成2年)
• Short form: H2
• Zodiac: Horse (庚午)

A year in which the era changed shows both eras when you enter only the year. For 1989:

• Showa 64 (昭和64年), until January 7
• Heisei 1 (平成元年), from January 8

Adding the month and day settles the era. 2019, 5 and 1 give May 1, Reiwa 1 (令和元年), a Wednesday.

Converting a list

Each line pasted into "Convert a list" is converted to the other calendar and shown in a table of line number, input, Western date and era date. The side converted to (the Western date for a line written as an era date) is set in bold.

These forms are read. Full-width digits and symbols, surrounding spaces and single-character eras such as ㍻ and ㋿ are read as well.

• Era dates: 令和6年4月1日, 令和元年5月1日, 平成31年4月, R6.4.1, H2/4/1, S50-3-1, 昭50.3.1, H31
• Western dates: 2024年4月1日, 2024/4/1, 2024-04-01, 2024.4.1, 20240401, 2024

To avoid mistaking one year for another, the following are not read and show "Not read as a date":

• Two-digit Western years, such as 90/4/1
• Era dates without an era, such as 6.4.1
• Dates followed by a weekday or other text, such as 2024年4月1日（月） (delete the part in brackets before pasting)
• Month names, such as April 1, 2024

"Western date style" sets the Western column to April 1, 2024, 2024/4/1 or 2024-04-01. A line with only a year, or a year and month, is written as far as it goes, such as 2024/4 or 2024-04.

There are two ways to copy:

• Copy results: copies the converted date of each line, one per line, in the order you pasted them. Blank lines and lines that could not be converted stay blank, so pasting next to the original column in a spreadsheet keeps the rows lined up
• Copy table (TSV): copies a header row (Input, Western calendar, Japanese era) and every non-blank line, separated by tabs. A line that could not be converted has empty Western and era cells. A cell containing " or a tab is wrapped in " so that spreadsheets read it as one cell

Up to 1,000 lines are converted at once. Lines after that are left out, and the tool says so.

Era periods

The eras this tool covers, with their periods in the Western calendar:

• Meiji (明治): 1868 to July 29, 1912 (through Meiji 45)
• Taisho (大正): July 30, 1912 to December 24, 1926 (through Taisho 15)
• Showa (昭和): December 25, 1926 to January 7, 1989 (through Showa 64)
• Heisei (平成): January 8, 1989 to April 30, 2019 (through Heisei 31)
• Reiwa (令和): May 1, 2019 onward

An era year is the Western year, minus the era's first Western year, plus 1. As a shortcut, subtract 2018 from the Western year for Reiwa, 1988 for Heisei, 1925 for Showa, 1911 for Taisho and 1867 for Meiji.

Using it for resumes and forms

• When writing a birth year in era form, enter the full date of birth. The same Western year can fall in two eras: January 7, 1989 is Showa 64, and January 8, 1989 is Heisei 1
• The "Someone born this year" row shows the age a person born that year reaches on this year's birthday. Before the birthday, the age is one less
• Some forms ask for 令和1年 where others use 令和元年. Follow what the form asks for

FAQ

Is 元年 the same as year 1?

Yes. This tool writes the first year as 元年 in Japanese and as a number in the short form, such as R1. Either 元 or 1 works as input.

Why does a month or day in Meiji 5 or earlier give an error?

Japan adopted the present (Gregorian) calendar on January 1 of Meiji 6 (1873). Before that it used a lunisolar calendar, so months and days do not line up with Western ones. The change to Meiji, for example, took place on the 8th day of the 9th month of Keio 4 in the old calendar, which is October 23, 1868. This tool does not convert the old calendar, so for 1868 to 1872 it shows only how the years correspond. All of 1868 is treated as Meiji 1.

What happens with a year that does not exist?

A year past the end of an era, such as Heisei 32, is not converted. The tool reports that Heisei ended in year 31, on April 30, 2019. A date outside the era, such as May 1 of Heisei 31, is handled the same way.

Can it convert future years?

Yes. It assumes Reiwa continues. A future era change is not reflected.

How is the zodiac decided?

Each Western year gets its stem and branch pair from the sixty-year cycle, changing on January 1. Counting from the start of spring (risshun) or the lunar new year is not supported.

Is my input saved?

No. Everything runs in your browser and is gone when you reload the page.