Japanese Era Converter

Convert dates between the Gregorian calendar and the Japanese era calendar (wareki) across Meiji, Taisho, Showa, Heisei and Reiwa. Day-exact era resolution, gannen handling, and the Japanese-script date ready to copy.

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Day

Month

Year (CE)

Japanese era date

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Year

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Day of week

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ISO-8601 (Gregorian)

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Oppdatert: 2. august 2026

Japanese era converter. Wareki (和暦) to Gregorian dates and back.

A Japanese era converter turns a Gregorian date into its wareki form — Reiwa, Heisei, Showa, Taisho or Meiji — and back again. It reads the era from the exact day, so it also gives you the full date in Japanese script, the day of the week and the ISO date.

What Is the Japanese Era Calendar (Wareki)?

The Japanese era calendar, or wareki (和暦), writes a year as an era name plus a count that restarts with each emperor's reign: 2026 is Reiwa 8. The era name itself is the gengō (元号), also called the nengō (年号) in historical and genealogical writing, and the Western year — 2026 — is the seireki (西暦). Japan has assigned one era to one reign since 1868, a rule called issei-ichigen (一世一元), and the Era Name Act of 1979 put it into statute: an era name is set by cabinet order and changes only when the throne does.

Five eras have run under that rule. Reiwa began on May 1, 2019 and has no end date, because none has been set. Heisei covered January 8, 1989 to April 30, 2019; Showa, December 25, 1926 to January 7, 1989; Taisho, July 30, 1912 to December 24, 1926; and Meiji, October 23, 1868 to July 29, 1912. The converter's dropdown spells them without macrons; Shōwa and Taishō are the same two words.

Four of those five transitions land in the middle of a calendar year, and that is what makes wareki awkward to convert. 1912, 1926, 1989 and 2019 each carry two era years, so a year-only answer is a guess in exactly the years people ask about most. January 7, 1989 is Showa 64 while January 8, 1989 is Heisei 1 — one day apart, two labels, and a birth certificate from that week falls on one side or the other.

Only the year gets rewritten. Japan has used Gregorian months and days since January 1, 1873, so July 31 is July 31 whether you write 2026 or Reiwa 8, and February in Reiwa 6 has 29 days because 2024 was a leap year. The converter still needs the day and the month, because they are what decide which era the date belongs to.

Wareki is hard to avoid on paper. Japanese driving licenses began carrying both calendars during 2019, phased in prefecture by prefecture — Aichi from May 5, 2019, for instance — so a card can read 2028年(令和10年)12月26日. Older licenses, most government forms, insurance policies, contracts and the koseki family registers that genealogists work from give the era year alone. Developers meet it too: when Reiwa arrived, Windows, macOS, iOS, the JDK and the GNU C Library each shipped an update for the new era during 2019.

How to Convert a Wareki Date and Read the Result

The converter runs in both directions and recalculates as you type, with no button to press.

1. Choose the direction at the top: Gregorian → Japanese era to turn a Western date into wareki, or Japanese era → Gregorian to do the reverse.

2. In the wareki direction, pick the era from the dropdown — Reiwa (令和), Heisei (平成), Showa (昭和), Taisho (大正) or Meiji (明治). In the Gregorian direction there is no era field, because the tool works the era out from the date itself.

3. Enter the day and the year, and pick the month from its dropdown. The Gregorian year field is labeled Year (CE) and accepts 1868 onward; the wareki year field is labeled Year (era) and takes the plain number printed beside the era name, so 令和7年 is 7.

4. Read the result below the inputs.

Going Gregorian → Japanese era, the card shows Reiwa (令和) 8, July 31, and the caption underneath names the arithmetic for the era it resolved: Reiwa year + 2018 = Gregorian year. Going the other way, the card shows 31 July 2026 CE.

Three tiles sit under the card: the year on its own, the day of the week, and the wareki date in Japanese script. The year tile is the direct answer to "what year is Reiwa 8?" — 8 going one way, 2026 going the other. The weekday is identical in both calendars, because it comes from the same underlying day count. The third tile, labeled Japanese form (和暦), holds 令和8年7月31日, the string a Japanese document asks for, with a copy button beside it; a first year renders as 令和元年5月1日, using 元年 rather than 1年.

An ISO-8601 row below the tiles gives the Gregorian date as 2026-07-31, the international standard ordering that leaves no doubt about which number is the month. The card, the Japanese-form tile and the ISO row each carry their own copy button, so you can lift whichever one your paperwork wants.

If the era year you typed runs past the end of that era, the conversion still appears, and a warning comes with it naming the day the era ended and the era that owns the date.

Japanese Era Years and Their Gregorian Spans

Japanese era year	Gregorian span	What it marks
Reiwa 8 (令和8年)	January 1 – December 31, 2026	Reiwa year + 2018 = 2026; a full calendar year
Reiwa 1 (令和元年)	May 1 – December 31, 2019	Reiwa begins; Emperor Naruhito accedes
Heisei 31 (平成31年)	January 1 – April 30, 2019	The last four months of Heisei; Emperor Akihito abdicates April 30
Heisei 1 (平成元年)	January 8 – December 31, 1989	Heisei begins, the day after Emperor Showa's death
Showa 64 (昭和64年)	January 1 – 7, 1989	Seven days — with Showa 1, the shortest era year of the modern five
Showa 20 (昭和20年)	January 1 – December 31, 1945	The end of the Second World War
Showa 1 (昭和元年)	December 25 – 31, 1926	Seven days; Emperor Taisho dies and Showa starts the same day
Taisho 15 (大正15年)	January 1 – December 24, 1926	Taisho and Showa share the calendar year 1926
Taisho 1 (大正元年)	July 30 – December 31, 1912	Taisho begins
Meiji 45 (明治45年)	January 1 – July 29, 1912	Meiji and Taisho share the calendar year 1912
Meiji 6 (明治6年)	January 1 – December 31, 1873	Japan's first fully Gregorian era year
Meiji 1 (明治元年)	October 23 – December 31, 1868	The era name changes from Keio to Meiji; earliest date this converter accepts

The Era Offset Arithmetic

Y_{\text{CE}} = Y_{\text{era}} + K

$Y_{\text{CE}}$ = Gregorian year, counted from the Common Era
$Y_{\text{era}}$ = The year number counted inside the Japanese era
$K$ = The era's offset: 2018 for Reiwa, 1988 for Heisei, 1925 for Showa, 1911 for Taisho, 1867 for Meiji

Each era carries one constant, and that constant is the Gregorian year immediately before the era opened. Reiwa opened in 2019, so K is 2018 and Reiwa 8 resolves as

8 + 2018 = 2026

Run the same constant backwards to go the other way: subtract the offset from the Gregorian year to get the era year. 1995 − 1988 = 7, so 1995 is Heisei 7. 1945 − 1925 = 20, so 1945 is Showa 20.

The five offsets are 2018 (Reiwa), 1988 (Heisei), 1925 (Showa), 1911 (Taisho) and 1867 (Meiji). The caption under the result card prints whichever one applies to the date you entered, so you can carry the sum away and do it in your head next time.

The arithmetic on its own breaks at the four boundaries. Both sums are valid for 1989: 1989 − 1925 = 64 and 1989 − 1988 = 1. The month and the day decide which one is the real answer, which is why this converter asks for a full date rather than a year.

Worked Wareki Conversions

What year is Reiwa 8?

Set the direction to Japanese era → Gregorian, pick Reiwa, and type 8 in the year field. The year tile reads 2026, because the Reiwa offset is 2018 and 8 + 2018 = 2026. Reiwa 8 covers the whole of 2026, January 1 to December 31: once an era is past its first year, an era year and a calendar year line up exactly. First years are the short ones, which is why Reiwa 1 covers only May 1 to December 31, 2019.

Reading a Japanese driving license expiry

A newer Japanese license prints both calendars, so an expiry can read 2028年(令和10年)12月26日. Older cards and most paper forms print the era alone: 令和10年12月26日. Read that as era 令和 (Reiwa), year 10, month 12, day 26, then set the converter to Japanese era → Gregorian, choose Reiwa, and enter 10, 12 and 26. The card returns 26 December 2028 CE and the ISO row gives 2028-12-26, which is the form a renewal reminder or a foreign insurer will accept.

Writing a Western birthday in wareki

A form with three boxes marked 年 / 月 / 日 wants the era year, then the month, then the day. Take January 17, 1995: set the direction to Gregorian → Japanese era, enter 17, January and 1995, and the card reads Heisei (平成) 7, January 17. The tile labeled Japanese form (和暦) holds 平成7年1月17日 with a copy button, so the whole string goes into the boxes without you assembling it from an era name and a number. The day-of-week tile reads Tuesday, which is a quick sanity check against any record that names the weekday.

1989 holds two era years

Enter January 7, 1989 in the Gregorian → Japanese era direction and the card reads Showa (昭和) 64, January 7. Move one day forward to January 8, 1989 and it reads Heisei (平成) 1 (gannen), January 8. Emperor Showa died on January 7 and Heisei took effect the next morning, so Showa 64 lasted seven days in total, January 1 through January 7. A converter that accepts only a year cannot answer this question at all, and a document from that first week of January is exactly where the difference bites.

A document dated Heisei 31 in June

Heisei ended on April 30, 2019, and offices had stacks of forms with 平成 already printed on them. Japan's interagency agreement of April 1, 2019 on year notation settled what to do with those: a document that still shows 平成 keeps its legal effect, and 平成31年度 is read as 令和元年度. A June 2019 form can therefore carry a Heisei 31 date. Enter Heisei, 31, June and 1: the converter returns 1 June 2019 CE and raises a warning that Heisei ended on April 30, 2019 and that the date belongs to Reiwa 1. Both halves are the point — the arithmetic is what you came for, and the warning names the era the date falls in.

A koseki entry from the Meiji era

Japan's modern family-register system started in 1872, so a genealogist working a koseki meets Meiji dates constantly. Meiji 6 onward converts exactly: enter Meiji, 6, January and 1, and you get 1 January 1873 CE, the first day Japan ran on the Gregorian calendar. An entry from Meiji 5 or earlier is a different animal, because its months and days come from the old lunisolar calendar. The converter still gives the right era year — Meiji 5 is 1872 — but 明治五年三月十日 is not March 10, 1872, and no year-shift arithmetic can make it so.

Mistakes That Turn Into a Wrong Date

Converting the year and ignoring the day. Four of the five era changes fell mid-year, so 1912, 1926, 1989 and 2019 each contain two era years. A year-only conversion is a coin flip in exactly those four years, and those are the years people look up.
Writing 令和1年 instead of 令和元年. The first year of an era is 元年 (gannen), never 1年. Japanese readers will understand 令和1年, but it is the wrong form on an official document, and Microsoft's own guidance for the 2019 era change told developers to make sure their software printed 令和元年.
Assuming Showa 1 and Showa 64 were full years. Showa 1 ran December 25 to December 31, 1926 and Showa 64 ran January 1 to January 7, 1989. Both endpoints sit inside the era, so the count is inclusive: seven days each, not the six you get by subtracting one date from the other.
Assuming the era always changes on the day the emperor dies. It did from Taisho to Showa: Emperor Taisho died on December 25, 1926 and Showa 1 began that same day. It did not from Showa to Heisei: Emperor Showa died on January 7, 1989 and Heisei took effect on January 8. Reiwa followed neither pattern, because it followed an abdication — the name was announced on April 1, 2019 and took effect on May 1.
Treating pre-1873 wareki months and days as Gregorian. Japan ran a lunisolar calendar until the end of Meiji 5. Meiji 5, 12th month, 2nd day was followed directly by Meiji 6, 1st month, 1st day, which is January 1, 1873 — so Meiji 5/12/3 through 12/30 never existed as dates at all. For Meiji 1 through Meiji 5, only the era year converts reliably.
Confusing 和暦 (wareki) with 皇紀 (koki). Koki is the imperial year, counted from the legendary founding of Japan in 660 BC, so Koki = Gregorian year + 660. Koki 2600 is 1940, the year that gave the Mitsubishi A6M its "Zero" nickname. It belongs to pre-war artifacts rather than to modern paperwork.

Where This Converter Stops Being Exact

The earliest Gregorian date the converter will convert is October 23, 1868, the day the era name changed from Keio to Meiji. Enter a Gregorian date between January 1 and October 22, 1868 and the tool reports it as outside the range of the Japanese era calendar rather than inventing a Meiji 0 or a negative era year. Those months belong to Keio 4 and to the old lunisolar calendar, and neither is in this era table.

The wareki direction does not refuse, and that is deliberate. A first-year date whose month and day fall before the era was proclaimed still converts: Meiji 1, January 1 returns 1 January 1868 CE, and Reiwa 1, January 1 returns 1 January 2019 CE. Each comes with a warning that the date is earlier than the era it names, alongside the day that era began. It is the mirror of the warning for an era year that runs past its era's end, and only a first year can reach it — from year 2 onward the arithmetic has already carried the date past the era's start.

Historically, Meiji 1 reaches further back than the tool does. The proclamation of October 23, 1868 renamed Keio 4 to Meiji 1 retroactively, all the way back to its first day, January 25, 1868. The era year for that stretch is therefore Meiji 1, but the converter starts at the proclamation, because that is the boundary the modern era table defines.

Months and days are exact from January 1, 1873 onward. Between October 23, 1868 and December 31, 1872 — Meiji 1 through Meiji 5 — Japan was still running the lunisolar Tenpo calendar, so a koseki entry written 明治三年五月十日 names a lunar month and day whose Gregorian equivalent sits several weeks away from May 10, 1870. The converter maps the era year correctly and passes the month and day through untouched, which is correct for anything dated from 1873 onward and misleading for anything earlier.

Pre-Meiji eras are out of scope. Japan adopted the era system in 645, starting with Taika, and has named more than 230 eras since; published lists differ on the exact total, because they disagree about which disputed eras belong on it. Every one before Meiji 6 sits on the lunisolar calendar, so covering them means implementing a second calendar rather than lengthening a list of names.

A future era is not representable either. Reiwa has no end date here because none exists yet; a successor would need a new entry in the era table, exactly as Reiwa itself did in 2019. And the result is a calendar conversion, not a certified translation — a registrar or an immigration office may still want the underlying document rendered by a sworn translator.

Wareki Vocabulary

和暦 (wareki)

The Japanese era calendar: a year written as an era name plus a count that restarts with each reign, such as Reiwa 8.

西暦 (seireki)

The Western, Gregorian year — 2026. Japanese forms often ask you to circle 西暦 or 和暦 before writing the number.

元号 (gengō)

The era name itself, such as 令和. Set by cabinet order under the Era Name Act, and changed only on imperial succession.

年号 (nengō)

An older synonym for 元号, still standard in historical and genealogical writing. The same system under a different word.

元年 (gannen)

The first year of an era, written in place of 1年. The first year of Reiwa is 令和元年, and it runs from the accession day to December 31.

一世一元 (issei-ichigen)

One reign, one era. The rule Japan adopted with Meiji in 1868, under which an era name lasts exactly as long as the reign.

皇紀 (kōki)

The imperial year, counted from the legendary founding of Japan in 660 BC. Kōki = Gregorian year + 660, so Kōki 2600 is 1940.

Era Name Act (元号法)

Act No. 43 of June 12, 1979, which put the era system into statute: era names are set by cabinet order and change on imperial succession.

Japanese Era Converter FAQ

What year is Reiwa 8?

Reiwa 8 is 2026. The Reiwa offset is 2018, so Reiwa year + 2018 = Gregorian year. Reiwa 8 runs the full calendar year, January 1 to December 31, 2026.

How do I convert a Japanese era date to a Western date?

Choose the Japanese era → Gregorian direction, pick the era from the dropdown, then enter the era year, the month and the day. Reiwa 8, July 31 comes back as 31 July 2026 CE, and the ISO row restates it as 2026-07-31 for forms that want that shape.

Is 1989 Showa 64 or Heisei 1?

Both. January 1 to January 7, 1989 is Showa 64; January 8 to December 31, 1989 is Heisei 1 (元年). Emperor Showa died on January 7 and Heisei took effect the following day.

What does gannen (元年) mean?

元年, read gannen, is the first year of an era. Japanese convention writes 令和元年 rather than 令和1年, and the same holds for 平成元年, 昭和元年, 大正元年 and 明治元年. A first year runs from the accession day to December 31, so it is almost always shorter than a calendar year. This converter prints the 元年 form automatically whenever the era year is 1.

Why does the converter ask for a month and a day, not just a year?

The era changes on a specific day, not on January 1. Four of the five transitions happened mid-year, so 1912, 1926, 1989 and 2019 each contain two era years, and only the month and day decide which one applies. A year-only converter has to guess in those four years.

Should I write Heisei 31 or Reiwa 1 on a document dated in 2019?

Heisei 31 for a date between January 1 and April 30, 2019, and Reiwa 1 (令和元年) from May 1 onward. The era that owns a document is the era its date falls in, whatever is pre-printed on the form, and Japan's interagency agreement of April 1, 2019 on year notation kept those pre-printed forms valid: a document still showing 平成 is read as its Reiwa equivalent. Type your date into the converter and it will name the era that owns it, with a warning if the two disagree.

How many days did Showa 64 last?

Seven: January 1 through January 7, 1989. Showa 1 was also seven days, December 25 to December 31, 1926. Count both endpoints — subtracting one date from the other gives six and undercounts by a day.

How do I write my birthday in wareki?

Set the direction to Gregorian → Japanese era, enter your birth date, and read the tile labeled Japanese form (和暦). For January 17, 1995 it holds 平成7年1月17日, which is exactly what a form's 年 / 月 / 日 boxes want, and a copy button sits next to it. The card above gives the same date in English as Heisei (平成) 7, January 17.

What is the earliest date this converter handles?

October 23, 1868, going from Gregorian to wareki. Earlier dates in 1868 fall under Keio 4 and Japan's old lunisolar calendar, so the tool reports them as outside its range instead of guessing. Coming the other way it does not refuse: Meiji 1, January 1 converts to 1 January 1868 CE and warns that the date is earlier than the era it names. Month-and-day conversion becomes exact from January 1, 1873, when Japan adopted the Gregorian calendar.

When did Japan switch to the Gregorian calendar?

On January 1, 1873, which the government designated as Meiji 6, 1st month, 1st day. The day before it was Meiji 5, 12th month, 2nd day, so the rest of that twelfth month never happened and Meiji 5/12/3 through 12/30 do not exist as dates. Everything from Meiji 6 onward uses Gregorian months and days.

Is this Japanese era converter free to use?

Yes. It runs in your browser at no cost and needs no account. Convert in either direction as often as you like, and copy the Japanese-script date straight out of the result.

How accurate is the conversion?

The era boundaries match the dates set by cabinet order and published in Unicode CLDR: Reiwa from May 1, 2019, Heisei from January 8, 1989, Showa from December 25, 1926, Taisho from July 30, 1912 and Meiji from October 23, 1868. Inside those bounds the conversion is exact, because only the year label changes and the months and days pass through unaltered. Before January 1, 1873 the month and day are lunisolar and cannot be converted this way.

Why do software libraries disagree about when the Meiji era started?

The proclamation date is a lunisolar date, Meiji 1/9/8, and it is easy to read that 9/8 as a Gregorian September 8. That is where the value 1868-09-08 came from, and it sat in the Unicode CLDR era data — and in .NET's JapaneseCalendar with it — for years, 45 days early. CLDR ticket 11375 corrected the Meiji start to 1868-10-23, and .NET's JapaneseCalendar.MinSupportedDateTime moved to that date in .NET 11 Preview 1. Java's java.time takes a different route and refuses everything before Meiji 6, January 1, 1873. This converter uses October 23, 1868.

Will the converter handle the next era?

Not until it exists. Reiwa has no end date in the era table because none has been set, so every date from May 1, 2019 onward resolves to Reiwa. A successor needs a new entry, which is the change calendar libraries across the industry made in 2019: the name Reiwa was announced on April 1 and took effect on May 1, and Windows, macOS, iOS, the JDK and the GNU C Library each shipped an update for it that year.

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