It’s a new year,1 and that means a new calendar. My new calendar, given to me by a mysterious benefactor, is a Japanese calendar with very nice pictures of Japanese castles. One thing I did not expect is for each date in the calendar to be annotated with an additional label in Japanese, in a mostly six-day cycle. It turns out that this is a system called Rokuyō (六曜) which came to Japan (from China, of course) towards the end of the Kamakura period.(ja.wp:六曜)

Rokuyō was supremely easy to use: just add the number of the lunar month to the number of the day in the month, and look at the remainder when divided by six.2

  1. Daian3 (大安): an auspicious day. Good for ceremonial occasions. The kanji literally mean “great peace”.
  2. Shakkō (赤口): unlucky except for the hours around noon, which are auspicious. Be careful with fire and sharp things. Literally “red mouth” (a Taoist reference).
  3. Senshō (先勝): lucky in the morning, but inauspicious in the afternoon; getting things done quickly is advised. Literally “victory before”.
  4. Tomobiki (友引): good day for trials and competitions, but bad for funerals. Lucky in the morning, unlucky around noon, and very lucky in the evening. Literally “friends pull”.
  5. Sembu (先負): basically the opposite of Senshō: unlucky in the morning and auspicious in the afternoon. Avoid haste and judgment. Literally “loss before”.
  6. Butsumetsu (仏滅): a very inauspicious day. Horrible for ceremonial occasions,4 but good for memorial services. Exercise restraint. Literally “Buddha’s death”.

The auspiciousness of a given day was a big deal. In fact, in much of Japanese history this and other astrological concerns were primary reasons for maintaining the calendar.(Lunar) Auspicious days were strongly favored for major events such as adopting a child, as recounted in the late-10th-century Kagerō Diary;(TJL:245) issuing a decree, as recorded in the 11th-century Tale of Flowering Fortunes;(CJP:206) and holding a wedding, as in the late Muromachi period street performers’ tale Shintokumaru.(TJL:1172)

In addition to ceremonial events, examples of travels being structured around these day categories can be seen in many places in Japanese literature. In the Kagerō Diary, we find, as the author sets out on a pilgrimage: “However, the day I decided on is inauspicious, so we make a pro forma start a day earlier, staying the night around the neighborhood of Hōshō Temple.”(TJL:230) The author goes to the trouble of spending the night at a temple in town to work around the restrictions of the Rokuyō. Similarly, in the Sarashina Diary, from around 1059, the author recounts making a similar preliminary start on a journey to the capital to allow the group to technically leave on the Daian instead of the Shakkō.(TJL:455)

The Japanese weren’t content with just this simple astrological system, however. In addition to the Rokuyō, there were days of abstinence (monoimi/物忌) for individual people, determined by astrologers, where one would stay isolated indoors, seeing no visitors, fasting, and generally abstaining from all activity.(TJL:256) Then we have auspicious and inauspicious directions, which also feature heavily in Japanese literature. We’ll explore those next week.

For now, if you’re ever wondering whether a particular day is a good day for an important undertaking, feel free to consult my Rokuyō script. I take no responsibility for your actual luck, however.

Footnotes:

  1. by the Gregorian calendar, of course; before 1873, Japan used a lunisolar calendar imported from China,(Lunar) and thus celebrated the New Year at Chinese New Year.
  2. Even today, Rokuyō is figured on the old lunisolar calendar, which means the six-day cycle jumps at the start of each lunar month.
  3. These are the modern names; different names have been used in different periods. Each of these names (except Butsumetsu) has multiple equivalent readings.
  4. Though nowadays you can get a discount renting wedding sites by having your wedding on Butsumetsu.