In 'Norito' in Fascicle (Book) 8 of the "Engishiki" (an ancient book for codes and procedures on national rites and prayers), it is described as 'Minazuki-no-tsugomori-no-oharae' (oharae on June 30) with a note 'Follow this procedure in the oharae in December.'
『延喜式』巻八「祝詞」には「六月晦大祓」として記載されており、「十二月も此に准へ」と注記がある。