To provide an easy-to-use permanent calendar capable of easily displaying a date by corresponding first to a seventh date displaying member to a day of the week per month and inserting the member from the upper side of a base board.

A permanent calendar includes: a day of the week displaying section 8 that displays seven days of the week; a base board 10 having a partitioning board 9, in which a plurality of window sections 22 are formed at the lower position of the day of the week displaying section 8; and first to seventh strip date displaying members 1, 2, 3, 4, 5, 6, 7 that are inserted from the upper side to be attached to the rear surface side of the partitioning board 9 of the base board 10, wherein seven kinds of number groups S in which numbers whose common difference is 7 are taken out from 1 to 31 and arranged to form an arithmetic progression are displayed in the first to seventh date displaying members 1, 2, 3, 4, 5, 6, 7, and the first to seventh date displaying members 1, 2, 3, 4, 5, 6, 7 are inserted from the upper side into the base board 10 so that the number groups S are corresponded to the calendar, and displayed in the window section 22 at the lower side of the day of the week displaying section 8.