Sashti or sixth day of the full moon and the sixth day of the new moon are favorite days for Lord Muruga. Several devotees of Muruga observe partial or full fast on each Sashti day and throughout the Kanda Sashti period.
The Sashti falling in on the waxing moon period in the month of Aippasi (October-November) is the day on which Muruga is believed to have killed a super-demon called Sura Padman. This is commemorated in the six-day festival of Kanda Sashti as a symbol of perpetual destruction of evil by God. Each of these six days is, by custom, set apart to recite the glory of Muruga from one of the six scriptures in His praise—Tirumurukarruppadai, Kandar Kalivenba, Kandar Anubhuti, Kandar Alankârâm, Kanda Sashti Kavacam, and Kanda Puranam. Giant-sized images of four asuras are moved on uplifted chariots and these encountered and destroyed by the Lord.
For this festival and for this only, the utsava deity of Chinnakumârar comes down from the hill temple, kills the asuras at four direction corners while on a festive procession round the hill and triumphantly returns to His abode in the hill. This is on the sixth day, i.e. sashti day. All the other events of the festival take place in the hill temple. On the seventh day, Muruga marries Valli. This divine marriage is celebrated both in the hill temple and in the Periyanâyaki Temple.