🔮 Japan Rokuyo Checker (六曜)

六曜 (ろくよう, rokuyō) are six day labels printed on most Japanese calendars that mark a day's traditional fortune. They are, in order: 先勝 (Senkachi, "victory if early"), 友引 (Tomobiki, "friend pull"), 先負 (Senmake, "defeat if early"), 仏滅 (Butsumetsu, "Buddha's death"), 大安 (Taian, "great peace"), and 赤口 (Shakku, "red mouth").

Two labels dominate everyday life in Japan. 大安 (Taian) is the most auspicious day - weddings are almost always booked on a Taian. 仏滅 (Butsumetsu) is considered the worst, and 友引 (Tomobiki) is traditionally avoided for funerals (the belief is that the deceased could "pull" friends along). You will see these on calendars, in wedding halls, and on lottery tickets issued by the government.

The 六曜 is calculated from the traditional lunisolar calendar (旧暦): it is (lunar month + lunar day) mod 6, mapped to the six names above. Because the lunisolar calendar drifts against the Gregorian one, the 六曜 of a Gregorian date changes year to year. Our tool computes the lunisolar date internally, so you just type a Gregorian date. For other date-based traditions, see the yakudoshi checker.

Internally the tool converts your Gregorian date into its lunisolar (旧暦) date - the lunar month and day. It then applies the classic rule: 六曜 index = (lunar month + lunar day) mod 6. A leap month (うるう月) follows the same sequence as the month it sits beside.

To make this exact without a fragile hand-written lunar algorithm, the tool carries a built-in table of lunisolar month starts from 1995 to 2055. For your date it finds the enclosing lunar month, counts the days since that month's first day, and computes the index. For example, the lunar New Year (month 1, day 1) is always 先勝, and the mid-autumn full moon (month 8, day 15) is always 仏滅 - both well-known fixed points that confirm the rule.

This means the 六曜 of, say, 14 February jumps around each year - in some years it is Taian, in others Butsumetsu. That is exactly why Japanese people look up the specific date rather than the Gregorian day of the week. If you are choosing a wedding day, pair this with our public holiday checker to avoid clashing with a national holiday.

1. Type a date (year, month, day) in the Gregorian calendar.
2. Click Check Rokuyo to see its 六曜.
3. The result shows the name, its reading, and its usual reputation.
4. Compare candidate dates to pick an auspicious one (大安 for weddings).
5. Remember the 六曜 changes each Gregorian year for the same month/day.

What is the best 六曜 for a wedding?

大安 (Taian) is the most auspicious and is the default choice for Japanese weddings. 先勝 (Senkachi) in the morning is also good. 仏滅 (Butsumetsu) is avoided for celebrations.

Why does the 六曜 of a date change each year?

六曜 is based on the lunisolar calendar, not the Gregorian one. As the two calendars drift, the same Gregorian date lands on a different lunar month/day each year, giving a different 六曜.

What does 友引 (Tomobiki) mean for funerals?

The word suggests "pulling a friend" - the superstition is that the dead could draw the living along. So funerals are traditionally not held on Tomobiki days, though the day is fine for weddings.

How is 六曜 actually calculated?

It is (lunar month + lunar day) mod 6, mapped to the six names. Our tool converts the Gregorian date to its lunisolar date internally using a built-in month table, so you do not need to know the lunar calendar.

Is 仏滅 always unlucky?

In tradition, yes - it is the least favoured day for starting something new. But like all 六曜, it is folk belief, not a rule, and many people simply note it without changing plans.

Do leap months affect 六曜?

A leap month (うるう月) follows the same 六曜 sequence as the month beside it, so the rule still works without special handling.

For weddings, the gold standard is 大安 (Taian), and within Taian, many couples prefer a weekend or a day near a holiday so guests can attend. The next best is 先勝 (Senkachi) in the morning. Avoid 仏滅 (Butsumetsu) for celebrations, and note that 友引 (Tomobiki) is fine for weddings but traditionally avoided for funerals.

Because the 六曜 is lunisolar, the "lucky" Gregorian dates shift every year - there is no fixed calendar day that is always Taian. If you are planning ahead, check the specific year. You can also look at the day's position relative to the new moon: Taian tends to cluster in the middle of the lunar month. For a fuller traditional picture, combine the result with the zodiac calculator when choosing an auspicious year as well as day.