noun
perpetual calendar for auspicious/inauspicious days
A traditional Japanese calendar used to determine lucky and unlucky days for events such as weddings, funerals, and travel. Often consulted for 六曜 (rokuyō) and other fortune-telling purposes.
結婚式の日取りを決めるために、母が万年暦を調べていた。
My mother was consulting a perpetual calendar to choose the wedding date.