When was Professor Kano Born?

Google query results for When was Professor Kano Born, retrieved 15 Apr 2020

Have you ever searched for Professor Kano's birthday in Google and gotten a result like that shown above? Is that right?

I started reading a new biography of Professor Jigoro Kano today. On the first page, it said he was born on December 10, 1860, just like the Google search result. That surprised me, because I thought I knew that his birthday was October 28, 1860.

I realized that this new book was a translation of a Japanese text, and the translator (or the original authors) did not realize that their audience would not recognize that a date prior to 1873 in Japan used the "lunar calendar," and not the Gregorian calendar common in the West. This site goes into great detail on the intricacies of the Japanese system.

Japanese Wikipedia

You can see these different calendars on the Japanese Wikipedia page for Prof Kano.

Professor Kano Japanese Wikipedia page, retrieved 15 Apr 2020

At the very top, we see the following:

嘉納 治五郎（かのう じごろう、1860年12月10日〈万延元年10月28日〉 - 1938年〈昭和13年〉5月4日）

The first two sets of characters -- 嘉納 治五郎   かのう じごろう -- are Prof Kano's name in two different formats, Kanji and Hiragana.

You can translate the Hiragana characters thus:

か   の  う  じ  ご  ろ   う
ka   no  u    ji   go  ro    u

In the dates, the characters 年, 月, 日, mean year, month, day.

The first date -- 1860年12月10日 -- is December 10, 1860, using the old lunar calendar. This appears to be the "default" date because it was the style used when Kano was born, prior to the adoption of the Gregorian calendar in Japan, which happened in 1873.

The second date -- 〈万延元年10月28日〉-- begins with 万延, which means Man'en, the old Japanese calendar name for the period from March 1860 to February 1861, which includes Kano's birthday.

The second two characters -- 元年 -- mean "the first year of", so 万延元年 means the first year of the Man'en era.

10月28日 refers to October 28. In other words, by the Gregorian calendar, Kano was born on October 28, 1860.

The last date -- 1938年〈昭和13年〉5月4日 -- is his death.

Kano died in 1938, year 年 13 of the Shōwa period -- 昭和13 -- on May 4 -- 5月4日. I assume the date is given in the Gregorian format because Japan had abandoned the lunar calendar at that point.

English Wikipedia

Notice Kano's English page only gives Gregorian (Western) dates, and his name in Kanji. His birthdate is October 28, 1860, according to the Western dating method.

Professor Kano English Wikipedia Page, retrieved 15 Apr 2020

So there you go. If you want to celebrate Kano's actual birthday, use October 28. If for some reason you prefer December 10, I suppose that's worth another party too!

 UPDATE: In October 2020, the Kodokan published this post explaining the issue.