These are the characters that are used on the calendar.
But why were they chosen for the days of the week?
What are the origins of the days of the week in Japan?
I'll explain it.
Contents
A Chinese idea called 七曜.
Originally, these seven characters came from a Chinese thinking of "Shichiyo" (七曜).
Shichiyo represents seven bright stars that were observed from the Earth.
The seven stars are the Sun, the Moon, Mars, Mercury, Jupiter, Venus, and Saturn.
I introduced the origin of the characters, "日" and "月" in this post.
The other planets are called as seen below:
| kanji | yomi | planets |
|---|---|---|
| 火星 | かせい kasei | Mars |
| 水星 | すいせい suisei | Mercury |
| 木星 | もくせい mokusei | Jupiter |
| 金星 | きんせい kinsei | Venus |
| 土星 | どせい dosei | Saturn |
Why are these characters used for the planets?
The five characters (火 水 木 金 土) are used for these five planets.
Where on earth did these characters come from?
The reason is also relevant to a Chinese thinking called "Gogyo" (五行).
Gogyo is a thought that everything is made from five elements, 火fire, 水water, 木tree, 金gold and 土earth.
These five letters are used for the five planets.
According to a theory, around the 8 century, a Japanese priest named 空海(kukai) brought this Chinese thinking to Japan.
You can see these Chinese thinking in a Japanese historical record written in the Heian period(794 - 1185).
It was around the Meiji period (1868 – 1912) that Sundays were set as holidays and started the week.
It is because they integrated the christian thought that Sundays are holidays.
Kanji practice sheet
I prepared practice sheet.
If you are interested, please download it.
