The Japanese days of the week seem quite different from anything in
Western languages:
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
J orthography
日曜日
月曜日
火曜日
水曜日
木曜日
金曜日
土曜日
Hiragana
にちようび
げつようび
かようび
すいようび
もくようび
きんようび
どようび
Romanisation
nichiyōbi
getsuyōbi
kayōbi
suiyōbi
mokuyōbi
kin'yōbi
doyōbi
Meaning
'Sun day'
'Moon day'
'Fire day'
'Water day'
'Wood day'
'Gold day'
'Earth day'
The initial impression is one of primitivity and mystery. The first
Chinese character in the name of each day is a simple concept linked
with an elemental force of nature such as fire, wood, water, etc. The
final character 日 hi, here pronounced bi, means 'sun' or 'day'. The
middle character 曜 yō, though familiar to Japanese speakers through
its use in the days of the week, is relatively obscure. Yōbi (曜日) is,
to all intents and purposes, a single expression meaning 'day of the
week'.
Yet the key to understanding the names of the days of the week lies in
that obscure second character 曜. Pronounced yào in Mandarin Chinese, 曜
means 'sunlight' or 'luminary; shining body'. The sun, the moon, and
the five planets were called the 'seven luminaries' (七曜 qī yào) by the
ancient Chinese, much as the ancient Greeks and Romans referred to
them as the seven planets. It is from the 'seven luminaries' that the
Japanese days of the week are derived.
The first two days of the week are named after the sun and the moon,
which represent the male principle (陽 yáng, Japanese yō) and the
female principle (陰 yīn, Japanese in) respectively. To understand the
remaining five we must look at the ancient Chinese theory of the 'Five
Elements' 五行 (wǔ-xíng). The Five Elements started out as a primitive
system for explaining the universe but gradually developed to become
an all-embracing cosmological system. Each element was equated to
(among others) a direction, a colour, a season, a time of day, a
planet, and a musical note in the pentatonic scale.
Fire (火 huǒ) was equated to south, red, summer, midday, the planet
Mars, and note 5 in numbered musical notation.
Water (水 shuǐ) was equated to north, black, winter, midnight, the
planet Mercury, and note 6 in numbered musical notation.
Wood (木 mù) was equated to east, green, spring, dawn, the planet
Jupiter, and note 3 in numbered musical notation.
Gold or Metal (金 jīn) was equated to west, white, autumn, dusk, the
planet Venus, and note 2 in numbered musical notation.
Earth (土 tǔ), was equated to the centre, yellow, 18 days at the end of
each season, the planet Saturn, and note 1 in numbered musical
notation.
The first five planets of the solar system in Chinese, Japanese, and
Vietnamese are still named after the Five Elements. In Chinese and
Japanese, Mercury is called 水星 ('Water Star'), Venus is called 金星
('Metal Star'), etc. Vietnamese places the word Sao ('star') in front
of each element to form the name of the planet. (Note 2: Names of the
outer planets & earlier planet names)
火星
水星
木星
金星
土星
Ch
huǒxīng
shǔixīng
mùxīng
jīnxīng
tǔxīng
J
kasei
suisei
mokusei
kinsei
dosei
V
Sao Hỏa
Sao Thủy
Sao Mộc
Sao Kim
Sao Thổ
Eng
Mars
Mercury
Jupiter
Venus
Saturn
So the Japanese days of the week are not a system of 'primitive
elements' after all! In fact, they run in parallel with days of the
week of the Ancient Greeks and Romans -- more closely in parallel,
indeed, than modern English:
Japanese
日曜日
月曜日
火曜日
水曜日
木曜日
金曜日
土曜日
Meaning
Sun-day
Moon-day
Mars-day
Mercury-day
Jupiter-day
Venus-day
Saturn-day
Latin
dies solis
dies lunae
dies Martis
dies Mercurii
dies Jovis
dies Veneris
dies Saturni
The obvious question is: could there be a historical link between the
'seven luminaries' and the 'seven planets' of Western and Middle
Eastern antiquity?
The answer is, yes. The most commonly accepted theory is that the use
of the seven planets originated in ancient Mesopotamia and Egypt, was
adopted by the Greeks and Romans, and then found its way to China.
However, the specific route and timing is not clear. The Cihai (辞海), a
Chinese encyclopaedia, carries the following entry for 七曜历 (七曜歴) qī
yào lì, or 'seven luminaries calendar':
七曜历 qī yào lì, i.e., method of recording days according to the 七曜 qī
yào. China normally observes the following order: sun, moon, Mars,
Mercury, Jupiter, Venus, and Saturn. Seven days make one week, which
is repeated in a cycle. Originated in ancient Babylon (or ancient
Egypt according to one theory). Used by the Romans at the time of the
1st century AD, later transmitted to other countries. This method
existed in China in the 4th century. It was also transmitted to China
by Manichaeans in the 8th century from the country of Kang (康) in
Central Asia (Note 3: The country of Kang).
The earliest use of the 'seven luminaries' (七曜 qī yào) is attributed
by Cihai to Fan Ning (範寧 / 范宁), a scholar who lived from AD 339-401.
Tellingly, the Chinese 'seven luminaries' were arranged in the same
order as the Middle Eastern planetary names for days of the week, and
not in the classic order of the Chinese five elements, which put water
before fire.
Besides the Manichaean route noted by the Cihai, there was also an
Indian route of transmission in the 8th century. The Chinese Buddhist
monk Yi Jing (義凈 / 义净) and the Ceylonese or Central Asian Buddhist
monk Bu Kong (不空, Amoghavajra) are both credited with referring to the
seven-day cycle of planetary names in their writings, drawing on
Indian sources. The Indians, in turn, appear to have taken this from
the West. (Note 4: The Buddhist route of transmission)
Although there were several routes of transmission into China, it
appears that the Indian route was the direct source of the Japanese
names for days of the week. In 806, the famous Japanese monk, Kobo
Daishi (弘法大師) (Note 5: Kobo Daishi) brought Bu Kong's writings back to
Japan along with a huge quantity of other Buddhist scriptures. Great
interest was taken in Bu Kong's astrological work by Japanese
astronomers, with the result that the planetary names found their way
into Japanese calendars of the time. One such calendar was used by the
Japanese statesman Fujiwara no Michinaga (藤原道長) for writing his diary
in 1007, in which the present-day Japanese names for the days of the
week can be found (Note 6: Fujiwara no Michinaga).
Although not in widespread use except for astrological purposes, this
system of names was nevertheless maintained by the Japanese right
through to the modern era. At one stage the days got out of kilter in
eastern Japan and had to be rectified by a calendar reform in 1685.
When they came under pressure to harmonise their working calendar with
the West in the latter half of the 19th century, the Japanese turned
to this old system to name the days of the week, officially adopting
them in 1876. After this the names gradually came into general use in
Japan (Note 7: The crucial step).
In China, on the other hand, the planetary names largely died out.
When the seven-day week was adopted under Western influence in the
modern era, the Chinese turned to a completely different system to
name the days of the week.
Incidentally, the Japanese word for 'week', 週 shū, is etymologically
derived from Chinese roots and has the meaning of 'cycle'. It has
since been borrowed into Chinese as one of the alternatives for
'week'.
