Japanese calendar converter


Demystifying Dates: Your Personal Time Machine to Japan!

Ever stumbled upon a Japanese date and scratched your head wondering what year it truly meant? Fear not, time traveler! The Japanese year converter is your portal to understanding the fascinating, and sometimes confusing, world of Japanese calendars.

Think of it like having a personal translator for history:

But wait, there's a twist! Unlike our linear Western calendar, eras in Japan change with each emperor's reign. Imagine being born in December 1926. One person born on the 14th might be in the 15th year of the Taisho era, while another born on the 30th could be in the 1st year of the Showa era! Talk about confusing birthdays!

This converter tackles that head-scratcher too, guiding you through the era shifts so you can confidently navigate Japanese dates.

Ready to embark on your time-traveling adventure? Simply pop in a Western or Japanese date, and let the converter whisk you away to a deeper understanding of Japanese history and culture.

Bonus Tip: Explore the different eras like Showa and Heisei to learn about their significance and historical context. You might even discover a new fascination with Japanese history!

Remember, a little knowledge goes a long way in appreciating other cultures. So, grab your converter and prepare to be amazed by the unique world of Japanese dates!

The Japanese calendar, also known as the Imperial calendar, is based on the reigns of the emperors of Japan. Each era begins with the ascension of a new emperor and ends with the emperor's death or abdication. The current era, Reiwa, began on May 1, 2019, with the ascension of Emperor Naruhito.

Each era is named after a phrase from classical Chinese literature and is numbered sequentially within the emperor's reign. For example, the current era is Reiwa 1 (令和元年, "Reiwa gannen" in Japanese).

The Japanese calendar uses the same months and days as the Gregorian calendar, but the years are numbered differently. In the Japanese calendar, the year is represented by the number of years since the start of the current era. For example, the year 2023 in the Gregorian calendar is Reiwa 5 in the Japanese calendar.


The era from a table that maps era names to their start dates. The start date is given as a year, month, and day in the Gregorian calendar.

Using the start date of the era and the year of the Japanese date, the code calculates the corresponding Gregorian year. For example, if the entered date is in Heisei 10, which started in 1998, and the year is 25, then the Gregorian year is 1998 + 25 - 1 = 2022.

The code then converts the month and day of the Japanese date to integers and creates a new Date object using the calculated Gregorian year, month, and day. If the resulting date is not valid (for example, if the day is greater than the number of days in the month), the code returns an error message. Otherwise, it displays the Gregorian date in the "gregorianDate" paragraph using the toDateString() method of the Date object.

Note that this is a simple implementation that assumes the Japanese date is in the format "era year month day" with full-width characters. It does not handle alternative formats, incomplete dates, or leap years. You can modify the code as needed to handle these cases.



The Japanese calendar uses a system of eras and years that starts with the accession of a new emperor. Each era has a name, such as Meiji, Taisho, Showa, Heisei, or Reiwa, and is numbered sequentially within the emperor's reign. For example, the year 2023 in the Gregorian calendar corresponds to Reiwa 5 in the Japanese calendar.