The Gregorian system is the internationally accepted calendar system. Japan officially adopted a variant of the Gregorian in 1873. Before the adoption, Japan primarily used a seven day calendar system lunisolar system for roughly 1200 years. Some of the elements of the system carried over to the Gregorian.

Have you ever given thought about the names given to the days of the week? The naming scheme comes from the combination of the Chinese philosophies of yin-yang and the five Taoist elements.

Day 詞【ことば】 Derived from…
Sunday 日曜日【にちようび】 Sun (Yang)
Monday 月曜日【げつようび】 Moon (Yin)
Tuesday 火曜日【かようび】 Fire
Wednesday 水曜日【すいようび】 Water
Thursday 木曜日【もくようび】 Wood
Friday 金曜日【きんようび】 Gold (Metal)
Saturday 土曜日【どようび】 Earth

Very algebraic, eh? Now you can go around and impress your peers with this newfound knowledge.

But wait! Did you know that alongside the seven-day calendar systems used in the last 1400 years, there was another system used by the Japanese (and other parts of Asia)?

This secondary calendar system has a profound impact in many Japanese lives. If you have seen an Asian calendar, you may have noticed kanji under the numerals. These are the names of the days under the six-day calendar system known as the Rokuyō (六曜, literal translation roku = six and yo = weekday. The kanji combination makes sense!).

So, what is the the Rokuyō and how does it impact Japanese lives?

Want to learn about Rokuyo? Today is your lucky day!

The Rokuyō is a variation of the original that came from China around the 14th century. As mentioned earlier, Rokuyō comprised six cycling days that are based on astrology. Each day determines the level of auspiciousness. In other words, it’s a fortune telling calendar system. Oh, Japanese, you are so superstitious (If you haven’t yet, check out the superstition article I wrote a while back!).

The following are the six Rokuyō days in cycling order.

Day 漢字【かんじ】 Auspicious Level
aka Senkachi
aka Sakigachi
先勝 Good luck in the morning. Bad luck in the afternoon.
Tomobiki 友引 Good luck all day except noon.
aka Senmake
aka Sakimake
先負 Bad luck in the morning. Good luck in the afternoon.
Butsumetsu 仏滅 Represents the day Buddha died. Bad luck for the entire day. Wouldn’t poke at it with a stick.
Taian 大安 Good luck for the entire day. The most desirable day.
aka Shakku
aka Jakko
赤口 Bad luck all day except at noon.

These days cycle in order through each Gregorian month. For example, January 1st starts out as Senshō, January 2nd is Tomobiki, January 3rd is Senbu, and etcetera.

One variation of the Rokuyō has the first day of each month starting on a certain day depending on the month. January 1 starts out as Senshō, February 1 starts out as Tomobiki. March 1 starts out as Senbu. Are you starting to see the pattern? On the 7th month, the first day resets back to Senshō. Another version has Senshō  starting on January 1st and cycle through the six days until a new year begins.

How serious do some of the Japanese take into account the Rokuyō in their daily lives? Although the newer generation seem indifferent about it, the more mature group take the system into heavy consideration.

For example, about three times as many weddings are held on Taian than on Butsumetsu. Due to this huge difference in planning, rates for weddings held on Butsumetsu days are discounted heavily. Many major events other than weddings favor Taian over Butsumetsu.

Child birth on a Taian day is highly desirable. With the advances in modern medicine, many parents opt to induce labor if a desirable day is near or to delay the birth if the day falls under Butsumetsu. I’ll let you decide if this is a healthy, sane decision. I couldn’t find numbers relating to the Japanese, but in 2003 a study done in Taiwan saw a significant increased in scheduled births on auspicious days versus non-auspicious days1.

Just from glancing at the list, one would deduce that you wouldn’t want to plan anything important on Butsumetsu. That’s not always the case.

The kanji for Tomobiki literally translates to “pulling a friend.” Due to it’s name, it is considered bad luck to schedule any funerals on these days. What kind of dead friend would pull you to the death realm, anyway? Crematoriums are typically closed on this day. Good to know.

Also another good thing to know: some Shinto shrines close on Butsumetsu. If you ever plan on visiting one, be sure they are open on the day you are visiting!

Before the next time you decide to munch on some of that delicious mochi or perhaps a quick bite of eel and watermelon (great pairing of food items, I’m told), take a quick glance at this version of the Rokuyō calendar to make sure the day and time of day is aligned in your favor. According to this, yesterday was 4-4 and butsumetsu. How bad was your day, yesterday?

Why should you check this, though? Because Tofugu cares about each and every one of you!

Ahhhhhh ♥

[1] “Patients’ attitudes vs. physicians’ determination: implications for cesarean sections.” Soc Sci Med. 2003 Jul;57(1):91-6.

  • Michael

    Purely coincidental that my day was crappy yesterday :P

  • サラ

    I kind of have to giggle: I crashed my car this tuesday at 5 AM, which was apparently sakimake. Maybe there’s something to all this after all, hmm……

  • Fernando Vieira Machado

    loooooooved the KB references =D
    unfortunetaly I’ve got a job interview on a Japanese company next monday morning…

  • Mescale

    I have an appointment for a hair cut at 12:00 tomorrow.


  • Beautifulworld382

    I had the worst day ever yesterday :/ Strange….

  • koichi

    That is lucky!

  • Kimura Okagawa

    No wonder I had such an [EXPLETIVE REDACTED] time finding a parking spot yesterday… then again, it IS the first week of the quarter, and parking always sucks because the college keeps reducing the number of spots available for non-carpool students to use (which is a load of くそ because one of the carpool eligibility rules is that you must live within the city limits, and only 25% of the student body actually does). Other than that, I had a pretty good day yesterday. So that’s 僕 2, 仏滅 1?

    Edit: And it looks like Sakura-Con this year is Shakko-Sensho-Tomobiki…

  • koichi

    But I’m sure you’re having the BEST day today, right? Happy 大安 to all!

  • Viet

    Yeah.. My day was pretty bad. Lost all my Starcraft 2 laddar games last night.

  • koichi

    You shouldn’t have played 4v4 on 4-4 butsumetsu

  • Yeesha

    Hum, I had one of the best days ever yesterday… Maybe the 4s cancel out with the butsumetsu? xD Or it’s just a time-zone-thing… ^^

  • kuyaChristian

    Yesterday wasn’t too bad but I was really tired and burned out so I guess by coincidence, I had a crappy day. 

  • Foozlesprite

    I actually learned about this while watching the anime Shiki.  I’d see the names under the day of the week for each scene/episode, and I had to look it up.  Pretty much the whole anime takes place on Butsumetsu, which makes sense if you’ve seen the horrible luck they have lol.

  • Peptron

    Yesterday was a great day for me, and today has been one of the worst day I had in quite a while. I guess the 4-4 and butumetu (and taian) cancel each other out.

  • Julien Klein

    Cool! Now we finally understand the new desk calendar that my wife bought the other day! My guesses weren’t too far off base…

    Fortunately for me, fortune telling and astrology have no impact on my life, but I’m glad to finally understand the kanji before me. 

  • Nicole Yamagawa

    Ah, my birthday is on Senbu.. Good to know!

  • Lee Rolfing

    My birthday this year is on 赤口…But I was born just after Noon so I guess I’m ok…

    Wait a minute… does this take into account for Daylight saving time? 

  • Saikou

    There’s a small correction I’d like to add.

    The days of the week were not based on the elements directly. Rather, just like all other uses of the Gregorian calendar, they are based on the nearest five celestial bodies. Sun, Moon, Mercury, Venus, Mars Jupiter and Saturn (which were the only ones that could be seen back when of this stuff was still being figured out.)

    They thought that each celestial body ruled an hour of the day in the order of Saturn, Jupiter, Mars, Sun, Venus Mercury Moon. There are only 24 hours in a day, which does not neatly divide into seven. This means that the first our of each day would be ruled by a different planet, and it was said that this planet, therefore, ruled the entire day as well.

    The order of the ruling day was Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn; it’s these planets which give the names of our weekdays.

    It’s a lot easier to see the connection in a language like French or Italian. In English, you can still see a few of the connections. Saturn for Saturday, Sun for Sunday, Moon for Monday. The others were changed slightly to the names of the Norse gods which, like the Greek/Roman gods, were associated with a celestial body. For example Thor had Jupiter (makes sense, both Jupiter and Thor were thunder gods after all) and thus he’s given Thursday.

    This link is much more apparent in Japanese as the names of the planets where based of the Chinese elements, not on gods, and assigned their name based on how the looked.

    Ignoring the sun and the moon we have:

    水星 すいせい Mercury, the water planet (Perhaps they thought it looked like it had water when they first saw it)

    金星 きんせい Venus, the metal planet (Its atmosphere is so thick that you can forgive them for thinking it was a metallic ball)

    火星 かせい Mars, the fire planet (It’s red… Fire’s red too!)

    木星 もくせい Jupiter, the wood planet (Considering the lines going down and the famous storm, from afar Jupiter certainly can resemble wood grain)

    土星 どせい Saturn, the earth planet (Because they had one element left and another day to fill, if you can find a better reason, please tell me).

    The Chinese used to just take the first hanzi of each planet and stick the hanzi for weekday. The Japanese adopted this system and are still using it today.

  • Saikou

    Japan doesn’t do daylight savings time, so probably not.

    But then, perhaps that would mean that your luck should be determined by what time it is in Japan rather than what time it is for you.

  • Beliar

    Hmm, can’t remember having a really bad day on the 4th, but I had kind of a bit of luck yesterday (The 5th). Nothing that important though, sadly.

  • Shirley

    yesterday was such a crisis at work O.O

  • Chiisana_Hato

    Yesterday was my last day at work. I got laid off. Got any graphic designer jobs? Curse you Rokuyo!

  • Sebbe

     The 20th of June should be 仏滅, right? Or is there something special that particular day?

  • James :D

    I can only hope I wasn’t the only person to write these down on my calendar.

  • Viet

    Thanks for the add-in. You are correct that the names are directly related to the elements, but the relationship is still there!

  • D.A.

    My birthday June 8  仏滅. 

  • Maegan.Mizu.Tiger

    My Birthday is Tomorrow (June 3rd) And the third is an Taian, but the month is a Shakko… WHAT DOES IT MEAN?!?!?! lol!

  • Fernando Vieira Machado

    Lol…. I was approved… and worked there for 1,5 year… AND IT WAS HEEEEEEELLLL AHAUHAUHAHAUAHUAHUAUAHUAUAUAHUAUA