The Jayakhya Samhita explains that pavithra protects one from evil. The puranas prescribe Pavithra Aaropana (adorning the deity with pavithra - sanctified garlands of thread), as an integral part of the rituals during the worship of Lord Vishnu. The Agni Purana specifies that the first day of a lunar fortnight either in the beginning of the month of Aashada or the end of the Krithika should be chosen for performing pavithrotsava. The Garuda Purana says that this rite should be done on the 12th day of the dark or bright fortnight.