Reiwa first day
Input
2019-05-01
Output
令和元年5月1日
KoguNavi tool
Japanese Era Converter
Convert dates between Japanese era notation and Gregorian calendar dates for forms, documents, and quick checks.
Local in browser
Runs in your browser for this tool.
Current tools are designed to run in your browser. As a general habit, avoid pasting passwords, private keys, or production secrets into any website.
This is date conversion only. It supports modern eras and does not handle historical calendar differences before Meiji.
What it helps with
- Fill Japanese forms that ask for era years
- Check dates in Japanese documents
- Convert Reiwa or Heisei dates for sharing
How to use
- Choose Gregorian to Japanese era, or Japanese era to Gregorian.
- Enter a date such as 2019-05-01 or 令和6年4月1日.
- Review the converted date and copy the result.
Examples
Heisei first day
Input
1989-01-08
Output
平成元年1月8日
Japanese era input
Input
令和6年4月1日
Output
2024-04-01
Good to know
- Supports modern eras only.
- Does not execute or validate anything beyond date conversion.
- Historical calendar differences before Meiji are not supported.
- Date interpretation uses the proleptic Gregorian calendar for simplicity.
FAQ
- Which eras are supported?
- Reiwa, Heisei, Showa, Taisho, and Meiji are supported.
- Does this validate historical calendar details?
- No. It uses the proleptic Gregorian calendar and does not model historical calendar changes before Meiji.
- Does it use an external API?
- No. The conversion is performed with built-in date logic in your browser.
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