Japanese Calendar Converter

In order to convert a date, a month, a year, or a name of an era in the Japanese calendar system to the western calendar system (the Gregorian or Julian calendar), you can use this Japanese calendar converter. This converter uses the API of HuTime

Why a Japanese calendar converter?

Until 1873, the lunisolar calendar was used in Japan. It was not the Gregorian calendar, which is commonly used in contemporary Western countries. 

From Japan's antiquity to the early Edo period, at least 5 calender systems were introduced, following developments in China:

The first of these is called the Senmyō calendar (宣命暦). It was used from 862 to 1685. 

Shibukawa Harumi, alias Shunkai (渋川春海, 1639-1715), an astronomer, developed a calendar system, called the Jyōkyō calendar (貞享暦) based on the Chinese Shoushi calendar (授时曆). This new calendar was implemented on February 4, 1685, and used for 70 years. 

In the course of the Edo period, three further calendar systems were developed in Japan:

  • Hōryaku calendar (宝暦暦), used between 1755 and 1798
  • Kansei calendar (寛政暦), used between 1798 and 1844
  • Tenpō calendar (天保暦), used between 1844 and 1872

Dates in Japanese historical sources are given according to these Japanese calendar systems. To know what time these dates point to according to the contemporary western dating system, a converter is useful. 

On January 1, 1873, the solar Gregorian calendar was introduced in Japan.