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Convert between Gregorian dates and Japanese eras with exact start dates, and work out age, school year and eto. Nothing is uploaded.
Today:
Year table: Reiwa, Heisei, Showa (with eto and age this year)
| Gregorian | Wareki | Eto | Age this year |
|---|
Exact era boundaries
Eras switch on their real start dates: Showa 64 ends on 1989-01-07 and Heisei 1 starts on 1989-01-08. Years that straddle two eras show both.
Flexible input
Accepts 令和6年4月1日, R6.4.1, H31/4/30, 平成元年, kanji numerals and full-width digits.
Age, school year and eto
Gives completed age, kazoedoshi, Japanese school grade with the April 2 to April 1 cut-off, and the sexagenary zodiac of the birth year.
>> technical info
How Wareki Conversion Works:
Japan numbers years from the start of each emperor's reign. The year is the Gregorian year minus the era's first Gregorian year, plus one, and the first year is written gannen (元年). Eras change on exact dates: Meiji 1868-01-25, Taisho 1912-07-30, Showa 1926-12-25, Heisei 1989-01-08, Reiwa 2019-05-01. Dates are counted as whole days with integer calendar math, so time zones never shift a result. Before 1873-01-01 Japan used a lunisolar calendar, so those dates are flagged.
Example:
2024-04-01 = 令和6年4月1日 = R6.4.1 1989-01-07 = 昭和64年1月7日 1989-01-08 = 平成元年1月8日
Why Use This Converter:
- >Date-precise era boundaries, not just year offsets
- >Both directions plus age, school year and eto
- >Understands R6.4.1, H31/4/30 and kanji numerals
- >Private: nothing leaves your browser
>> frequently asked questions
Q: Which year is the first year of Reiwa?
A: Reiwa 1 (令和元年) began on 2019-05-01 and the same Gregorian year 2019 is also Heisei 31 until 2019-04-30.
Q: How do I convert a Gregorian year to a Japanese year quickly?
A: Subtract 2018 for Reiwa, 1988 for Heisei, 1925 for Showa, 1911 for Taisho and 1867 for Meiji. Check the exact date when the year is an era change year.
Q: What is the difference between age and kazoedoshi?
A: Completed age counts full years since birth. Kazoedoshi is the traditional count: you are 1 at birth and gain a year every New Year, so it equals current year minus birth year plus 1.
Q: How is the school year decided?
A: Children born from April 2 to April 1 of the next year share a school year, and those born from January 1 to April 1 are called hayaumare (early-born). The school year changes on April 1.
Q: Why are dates before 1873 flagged?
A: Meiji 1 to 5 used the old lunisolar calendar. Their months and days do not match Gregorian months and days, so only the year is converted.
Q: Is my data uploaded?
A: No. Everything runs locally in your browser.