noun
day of Ten'ichijin's first ascension to heaven in a year
Rare term from traditional Japanese almanac (暦注). Refers to the 30th day of the first sexagenary cycle of the year, when the deity Ten'ichijin (天一神) is believed to ascend to heaven. Used in historical or folkloric contexts.
古い暦には、天一太郎という日が記されていることがある。
In old calendars, a day called Ten'ichitarō is sometimes recorded.
Compound of 天一 (Ten'ichi, the deity) and 太郎 (tarō, a common male name suffix often used for the first or primary instance). The exact historical derivation is uncertain; the term is part of traditional calendar lore.