🍀 Auspicious Days Finder (一粒万倍日 & 天赦日)

Beyond the well-known rokuyō calendar (six-day fortune cycle), Japanese tradition has special kichinichi (吉日, auspicious days) that are considered the luckiest dates for important events. Two of the most powerful are:

• Ichiryumanbaibi (一粒万倍日, literally "one grain becomes ten thousand times"): A day when any action begun will multiply greatly. Ideal for starting a business, opening a bank account, planting seeds, or making an investment. The name comes from the idea that a single grain of rice planted on this day will yield a 10,000-fold harvest.
• Tenshabi (天赦日, literally "heaven forgives day"): The most auspicious day in the almanac, when heaven pardons all. Ideal for any major life event — weddings, moving house, starting a new job, or launching a business. Occurs only 5-6 times per year.

When both fall on the same day, it's called 一粒万倍日・天赦日の重なる日 — an extremely rare and powerful lucky day that happens only once every several years. Many Japanese people try to schedule weddings or major events on these days.

These auspicious days are determined by the old lunisolar calendar's stem-branch system (干支). The calculation is based on which of the 60 zodiac combinations (六十干支) the day falls on, combined with the month and season. For the zodiac of any year, see our zodiac calculator.

Ichiryumanbaibi (一粒万倍日) is determined by the day's 干支 (zodiac stem-branch). It falls on specific zodiac days each month, based on the old calendar's month and the day's sexagenary position. The pattern varies by month but typically includes days with these stems and branches:

• 丑 (Ushi/Ox) and 寅 (Tora/Tiger) days in spring months
• 辰 (Tatsu/Dragon) and 巳 (Mi/Snake) days in summer months
• 未 (Hitsuji/Sheep) and 申 (Saru/Monkey) days in autumn months
• 戌 (Inu/Dog) and 亥 (Inoshishi/Boar) days in winter months

Tenshabi (天赦日) is even more specific. It occurs only when the day's zodiac matches one of six specific stem-branch combinations, and only in certain months. The six Tenshabi zodiac days are: 甲子, 甲戌, 甲申, 甲午, 甲辰, 甲寅 — but only when they fall in the correct season.

For the ultimate lucky day, Japanese almanacs look for Taian + Tenshabi + Ichiryumanbaibi all on the same day. These rare alignments drive wedding venue booking prices. For choosing wedding dates or business opening dates, combine this finder with the rokuyō calendar and the eho direction.

1. Type a date to check (e.g. 2026-04-13).
2. Click Check to see if it's an Ichiryumanbaibi or Tenshabi day.
3. The result shows all auspicious properties of that date.
4. Use the information for planning weddings, business, or events.
5. Combine with the rokuyo calendar for a full traditional reading.

What is Ichiryumanbaibi (一粒万倍日)?

Ichiryumanbaibi means 'one grain becomes ten thousand times.' It's an auspicious day when any action started will multiply greatly. Ideal for starting a business, opening a savings account, investing, or planting. It occurs about 5-7 days per month.

What is Tenshabi (天赦日)?

Tenshabi means 'heaven forgives.' It's the most auspicious day in the Japanese almanac, when heaven pardons all. Perfect for any major life event: weddings, moving, new job, or business launch. It occurs only 5-6 times per year.

What happens when Ichiryumanbaibi and Tenshabi fall on the same day?

This is an extremely rare and powerful lucky day (一粒万倍日・天赦日の重なる日), occurring only once every few years. It's considered the ultimate auspicious day for starting anything important. Wedding venues charge premium prices for these dates.

How are these auspicious days calculated?

They're based on the day's position in the 60-year sexagenary cycle (干支, eto). Ichiryumanbaibi falls on specific zodiac stem-branch days each month. Tenshabi occurs on six specific zodiac days (甲子, 甲戌, 甲申, 甲午, 甲辰, 甲寅) when they fall in the correct season.

Should I plan my wedding on an auspicious day?

It's a common practice in Japan. Wedding venues often charge more for Tenshabi or Ichiryumanbaibi dates. If you follow the tradition, combining Tenshabi + Taian (from the rokuyo calendar) is ideal. But the most important thing is choosing a date that works for your family.

Are auspicious days the same as the rokuyo calendar?

No, they're different systems. Rokuyo (六曜) is a six-day fortune cycle (Taian, Butsumetsu, etc.). Ichiryumanbaibi and Tenshabi are based on the sexagenary zodiac cycle. They can overlap — a Taian day that is also Tenshabi is the luckiest combination. Check our rokuyo checker for the six-day cycle.

In modern Japan, auspicious days are primarily consulted for weddings, business openings, moving house, and major purchases. Wedding venues often charge premium prices for Tenshabi or Ichiryumanbaibi dates. If you're planning an event, booking well in advance is essential for these popular dates.

Not all auspicious days are created equal. The most powerful combination is 天赦日 + 一粒万倍日 on the same day, which happens only every few years. The next major overlap dates are published in almanacs (暦, koyomi). For a full calendar reading, combine this with the rokuyō six-day cycle: a Taian (大安) day that is also Tenshabi is the gold standard. Avoid Butsumetsu (仏滅) and Tomobiki (友引) for major events. To find seasonal markers like Setsubun, see our Setsubun & eho finder.