What are Senjitsu?
Senjitsu is a collective term for special days on the calendar designated for judging the auspiciousness of each day. They are calculated from combinations of the sexagenary cycle, lunar calendar, and 28 Mansions, and are used for selecting dates for ceremonies, funerals, business openings, and more.
Senjitsu originated from Chinese calendar annotations and developed uniquely in Japan as a system for judging the auspiciousness of days. Days matching specific criteria — based on the sexagenary cycle (Jikkan Jūnishi), lunar calendar dates, positions of the 28 Mansions, and other elements — are designated as "auspicious" or "inauspicious."
Unlike Rokuyō, which simply repeats in a 6-day cycle, selected days appear under different cycles and conditions for each type, so multiple selected days can fall on the same date. The day when Tensha-nichi and Ichiryū Manbai-bi coincide is known as the "ultimate lucky day."
Auspicious day
| Name | Cycle | Description |
|---|---|---|
| Tensha-nichi | 5–6 times per year | The most auspicious day when heaven forgives all sins. Determined by the combination of season (solar longitude) and the sexagenary cycle. In spring it falls on Tsuchinoe-Tora, in summer on Kinoe-Uma, in autumn on Tsuchinoe-Saru, and in winter on Kinoe-Ne. Considered the best day to begin anything, and the most precious of all auspicious days. |
| Ichiryū Manbai-bi | 4–6 times a month | An auspicious day when "a single grain of rice will bear ten-thousand-fold fruit." Ideal for starting new businesses, opening stores, sowing seeds, and investing. However, borrowing money or things from others is inauspicious as debts will also multiply ten-thousand-fold. Calculated from the solar month and the day's earthly branch. |
| Ten'on-nichi | 5 consecutive days × 3 | An auspicious day for receiving heavenly blessings. Occurs in five consecutive days for specific groups of the sexagenary cycle. Good for celebrations and joyous occasions. Not to be used for inauspicious events. |
| Bokura-nichi | 4–6 times a month | A day when heaven nurtures people as a mother nurtures her child. Determined by the combination of the solar month and the day's earthly branch. Especially auspicious for marriage and construction. |
| Kishuku-nichi | 28-day cycle | A day corresponding to "Kishuku" (Ghost Mansion) of the 28 Lunar Mansions. Greatly auspicious for all things since demons stay in their lodging and do not go out. Also the day Buddha was born. However, only weddings are inauspicious. |
| Tora no Hi | 12-day cycle | A day corresponding to the Tiger in the Chinese zodiac. The tiger is said to "travel a thousand miles and return a thousand miles," making it auspicious for travel and financial fortune. It is also said that money spent will come back. |
| Mi no Hi | 12-day cycle | A day corresponding to the Snake in the Chinese zodiac. A Benzaiten festival day, auspicious for financial and monetary fortune. A good day to visit shrines dedicated to Benzaiten. |
| Tsuchinoto Mi no Hi | 60-day cycle | A day corresponding to Tsuchinoto-Mi in the sexagenary cycle. The most auspicious of all Snake Days and the most powerful Benzaiten festival day. Ideal for boosting financial fortune. |
| Kinoe-ne no Hi | 60-day cycle | The first day of the sexagenary cycle (Kinoe-Ne). Auspicious for new beginnings. Also a festival day of Daikokuten, making it ideal for starting new ventures. |
Auspicious Days in the Lower Calendar Notes
| Name | Cycle | Description |
|---|---|---|
| Daimyō-nichi (Great Light Day) | 24 out of 60 days | An auspicious day when heaven and earth open and the sun illuminates every corner. Especially good for construction, relocation, and travel. Said to mitigate negative effects even when overlapping with inauspicious days. Corresponds to 24 specific days in the sexagenary cycle. |
| Kamiyoshi-nichi (Divine Auspicious Day) | 33 out of 60 days | A day considered auspicious for all matters related to Shinto rituals. Ideal for shrine visits, ceremonies, prayers, Miyamairi, and Shichi-Go-San. Corresponds to 33 specific days in the sexagenary cycle, occurring frequently. |
| Gettoku-nichi (Moon Virtue Day) | About 3 times a month | An auspicious day for obtaining the virtues of the month. Considered auspicious for all things, especially good for construction, renovation, and extensions. Calculated from the heavenly stem of the solar month and the heavenly stem of the day, based on the principle of the Three Harmonies. |
| Ten'ichi Tenjō | 16 out of 60 days | The period when Ten'ichijin ascends to heaven. During this time, there are no directional taboos, and traveling in any direction is auspicious. Especially favorable for travel, moving, and relocation. Lasts 16 days from Tsuchinoto-Tori to Kinoe-Ne. |
Unlucky Days
| Name | Cycle | Description |
|---|---|---|
| Fujōju-bi | 8-day cycle | An inauspicious day when nothing is said to come to fruition. It cycles every 8 days based on the month and day of the lunar calendar. Anything started on this day is believed to not succeed, so weddings, store openings, contracts, and relocations are avoided. When it coincides with Tensha-nichi or Ichiryū Manbai-bi, the auspicious effect is said to be halved. |
| Sanrinbō | 2–3 times a month | A highly inauspicious day for construction. Building on this day is said to bring ruin to the three houses across and the neighbors on both sides. Especially unfavorable for roof-raising, erecting pillars, breaking ground, and relocation. Determined by the combination of the solar month and the day's earthly branch. |
| Jushi-nichi (Death-Receiving Day) | Once a month | The most dreaded highly inauspicious day in the lower calendar notes. Also called "Kurobi" (Black Day). This day is considered unlucky for all matters, and remains inauspicious even when overlapping with Tensha-nichi. Calculated from the lunar month and the day's earthly branch. |
| Jūshi-nichi (Ten Deaths Day) | Once a month | The second most inauspicious day after Jushi-nichi. Considered inauspicious for all things, unsuitable for all events except funerals. Calculated from the earthly branches of the lunar month and day. |
| Jippō-gure | 10 out of 60 days | A 10-day period from Kinoe-Saru to Mizunoto-Mi. Inauspicious for all matters because the Heavenly Stems and Earthly Branches are in conflict (sōkoku). Especially unfavorable for travel, marriage, and contracts. The name originates from "the energy of all ten directions is blocked." |
| Ōbon-do (Major Soil Violation) | 7 out of 60 days | A 7-day period from Kanoe-Uma to Hinoe-Ne. A period when disturbing the soil is considered inauspicious. Avoid groundbreaking ceremonies, erecting pillars, digging, sowing seeds, and civil engineering work. |
| Shōbonchi (Minor Earth Affliction) | 7 out of 60 days | A 7-day period from Tsuchinoe-Tora to Kinoe-Saru. An earth affliction period following the Major Earth Affliction. Begins after a one-day break (Hinoto-Ushi). Inauspicious for earthwork and starting construction. |
When Tensha-nichi and Ichiryū Manbai-bi fall on the same day, it is called the "Ultimate Lucky Day" — an extremely rare and precious auspicious day that occurs only a few times a year.
The power of Tensha-nichi, where "all is forgiven," combines with the power of Ichiryū Manbai-bi, where "what you start will multiply ten-thousandfold," making it the most suitable day for starting a new business, getting married, moving, and more.
However, even the most auspicious days may coincide with unlucky days such as Jushi (Death Day), Fujojubi (Day of Non-accomplishment), or Sanrinbō. This calendar determines fortune based on an overall score that factors in the influence of unlucky days.
On this calendar, Ultimate Lucky Days are highlighted in gold. You can check them on the auspicious day calendar.
Determination by Sexagenary Cycle
In the Japanese calendar, each day is assigned a sexagenary cycle sign (a combination of the 10 Heavenly Stems and 12 Earthly Branches). Days such as Tora-no-hi, Mi-no-hi, Tsuchinoto-Mi, and Kinoe-Ne are determined directly from this cycle.
Determination by Solar Month
Ichiryū Manbai-bi, Bokura-bi, Sanrinbō, and other calendar notes are determined by the combination of the "solar month" based on the sun's ecliptic longitude and the day's earthly branch. Since the solar month changes at the "setsu" divisions of the 24 solar terms (such as Risshun and Keichitsu), it differs slightly from the lunar calendar month.
Determination by Lunar Calendar
Fujōju-bi (Non-achievement Days) are calculated in an 8-day cycle from the month and day of the lunar calendar. Since the base date resets at the beginning of each lunar month, they appear irregularly in the Gregorian calendar.