Shashti is a day of importance to Sri Murugan. It usually falls a few days after Amavasai of the month. Sashti or sixth day of the full moon and the sixth day ofthe new moon are favorite days for Lord Muruga. Devotees undertake fasting andprayers on the occurrence of this day every month for a period usually a year orthree years. The occurrence of Shashti during the Malayalam month of Thulam (October-November) is considered of great importance and celebrated as Skanda Shashti. Devotees organise Bhajan and Kirtan programs on a grand scale. Severaldevotees of Muruga observe partial or full fast on each Sashti day and throughout the Skanda Sashti period. 

Skanda Shashti festival celebrates the appearance of Lord Murugan in this temporal world. It is the day on which Lord Subramanya defeated the demon Taraka. Murugan, representing the good, fights Tarakasuran, a demon who represents evil or the dark forces. It is interesting to note that this festival comes immediately after Navarathiri and Deepavali. Its symbolism is very similar to that of Deepavali and Navarathiri- Victory of good over evil. Narakasuran represents the dark forces and Lord Krishna represents the good. Similarly, Shakthi, the goddess representing the good, destroys the evil and dark forces represented by Mahishasuran after the nine night festival, Navarathiri. 

Another feature found in the Skandapuranam (the story of Lord Muruga), is that its similarity in some aspects to Ramayana. Like Sri Rama, Murugan also goes to war with Veerabadran and as in Ramayana, Murugan sends off the defenseless Tarakasuran to return the following day fully decked with weapons to fight him. Devotees fast for this period and meditate on the glory of Lord Murugan. Married couples who do not have any children offer their special prayers to seek Murugan's blessings for a child. 

It is a period when Lord Murugan's devotees recite the hymns Skanda Shasti Kavacham- the protective Armour of Lord Murugan. Skanda Shasti Kavacham is a short composition of powerful hymns containing special mantras. Through these matters, the composer, a sage cum poet Thevarayar, seeks Murugan's blessings to protect him against all evil forces such as the devils, goblins and protection of his body against all sickness. Though he had composed six such kavachams or Armour of hymns in honour of each of the six celebrated abodes of Murugan, the one composed at Thiruchendur is most popular and is recited by devotees. This is because, Thevarayar, who was despondent with his severe ulcer pain was cured at this abode of Murugan.