20, 10, 2, and 1 yen year 25 (1892) [solved]

https://en.numista.com/catalogue/pieces26999.html

"Comments
The year 25 coin was struck for exhibiton at the World's Columbian Exposition in Chicago in 1892"

The Exposition was held in 1893 not 1892 so these coins could not have been struck at the Exposition
https://en.wikipedia.org/wiki/World's_Columbian_Exposition

Maybe these coins were struck year 25 (1892) for the Exposition held in 1893.

According to wiki the Meiji era started on October 23, 1868. So I think October 23, 1868 counts as year 1. That means a Meiji era year spans two Gregorian years.

https://en.wikipedia.org/wiki/Meiji_(era)

So October 23, 1892 is the start of year 25 but it goes to October 22, 1893 or something i.e year 25 spans 1892-1893. And the Chicago Fair went from May 1, 1893 to October 30, 1893. So it's possible the coins were minted at the fair in 1893 in Meiji era 25.

This would be similar to how the French Republican calendar started on 22 Septemeber 1792 which means the French Republican years also span two Gregorian years.

The coins were struck in 1892 the sentence is indeed not clear enough I will change them.

The Japanese calendar is congruent with the Gregorian one since Meiji 6 (1873) and before then it was based on the Chinese Lunisolar calendar which also was just 1 or 2 months off.

Quote: "Idolenz"​The coins were struck in 1892 the sentence is indeed not clear enough I will change them.
​
​The Japanese calendar is congruent with the Gregorian one since Meiji 6 (1873) and before then it was based on the Chinese Lunisolar calendar which also was just 1 or 2 months off.

​Thank you! I did not know that the Japanese calendar is congruent with the the Gregorian one since 1873
https://en.wikipedia.org/wiki/Adoption_of_the_Gregorian_calendar#Japan
"Since 1873, an era and the first year of that era has begun on the day of the year that the emperor ascended the throne. The second year of that era began on the next 1 January even if the first year contained only a few days. All subsequent years of that era began on 1 January until that emperor died."