Informe número 41 - Dating modern Japanese coins

Dating modern Japanese coins

The Japanese counting system and number-related expressions are one of the difficult parts of learning Japanese. Numbers in Japanese can either be written in the usual "European" fashion (0...9), or using kanji. 0...9 is more often used when writing horizontally, kanji when writing vertically, although there are plenty of exceptions to both. When using kanji to write numbers, a positional system is employed. 25 is "two ten five", 1246 is "thousand two hundred four ten six", etc. Note that there is a character and word for 10,000 (man), but not for a million. To say a million, you have to say "one hundred ten-thousand".

The following number are the basic numbers used in dating Japanese coins:

Modern, post-WWII coins are quite easy to date. Japan does not use the calendar year of minting, but rather the year of reign of the emperor. To begin with, we must look at the emperors of this time frame, and understand their years of reign.

Hirohito, who used the regal name Showa, ruled from 1926 until 1989.
Akihito, who used the regal name Heisei, has ruled since 1989.

1926 would be Showa yr. 1,
1927 would be Showa yr. 2, etc.
1989 was Showa yr. 64.
1989 was also Heisei yr. 1, as he ascended the throne in that year.
1990 would be Heisei yr. 2, etc.

To read the date:

Find the legend (usually on the lower side of the reverse, under the English value on all except the 5 yen, which does not have an English value). This legend will contain either 4,5, or 6 Japanese characters. Reading the normal western style of left to right, the first 2 characters are the regal name of the emperor, either Showa or Heisei. The last character on the right is irrelevant (it means year). The characters in the middle are the important ones for dating.

Read the numbers left to right:

If there is only a single number, (between 2 and 10*), then that is the actual year of reign, and would mean that the coin is a Heisei issue. There is a special character for yr 1, which means "first".

If there are 2 numbers, and the first number is 10, then add the second number to it to get the year, such as 10 1 would be 11 (2001 is Heisei yr 13).

If there are 2 numbers, and the second number is 10, then multiply the first number by 10, such as 4 10 would be 40.

If there are 3 numbers, the second number should always be 10. Multiply the first number by 10, and add the third number, such as 4 10 5 would be 45 (4 x 10 + 5).

To determine the actual year of minting, it must first be determined under which emperor the coin was minted. Currently, that is not a problem since the years do not overlap. Current Japanese coins were begun in 1948, Showa yr 23.

If the coin is dated above 23, then it is a Showa issue. If the coin is a Showa issue, add the year of reign to 1926, and subtract 1. For example, Showa year 55 would be 1980: 1926 + 55 -1.

If it is dated under 11, then it is a Heisei issue. If the coin is a Heisei issue, add the year of reign to 1989, and subtract 1. For example, Heisei year 8 would be 1996: 1989 + 8 - 1.