Kanda Sashti runs for six days from the new moon of the Tamil month Aippasi, in October or November, and it is kept as a fast. Devotees take one meal a day or none, attend the temple through the six evenings, and hear or recite the Kanda Sashti Kavacham, a protective hymn addressed to Murugan that is among the most widely known Tamil devotional texts in daily use.
The sixth day carries the Soorasamharam, the destruction of Surapadman, which is not narrated but performed. At Tiruchendur on the coast of the Gulf of Mannar, where the largest observance is held, the god is brought out in procession to the shore and the battle is staged in the open before an assembly that can run into the hundreds of thousands. Effigies of the asura brothers are struck down in sequence, and the final confrontation with Surapadman ends with the vel, the spear, and with the transformation of the enemy into the peacock and the cock.
The following day is the Thirukalyanam, the marriage of Murugan and Deivanai, so the cycle closes on a wedding rather than on a killing. That order is the point of the festival. Other temple towns keep the same six days on their own scale, and the observance has travelled with Tamil migration into Sri Lanka, Malaysia, Singapore, South Africa and the Caribbean, where the fast is kept in temples built long after the story was fixed.