Skanda Sashti, also known as Kanda Sashti, is the most important festival dedicated to Lord Murugan. Skanda Sashti is observed mainly by Tamil Hindus. The day of Skanda Sashti is decided based on lunar month and it falls during sixth day of Karthika Masam.
During Kanda Sashti, devotees observe six days fasting which starts from first day or Pirathamai of Karthika lunar month and ends on the sixth day which is known as Soorasamharam day. Soorasamharam is the final and the most important day of the six days festivities. It is believed that Lord Murugan defeated Demon Surapadman on the very same day and the festival of Soorasamharam is observed every year to mark the victory of good over evil.
It is important to note that the day when Shasti Tithi conjugates with Panjami Tithi is chosen for Soorasamharam Vratam. Hence most temples observe Kanda Sashti on Panjami Tithi if Shasti Tithi starts before sunset on Panjami Tithi.
Kanda Sashti celebrations at Thiruchendur Murugan Temple are the most famous one. The six days celebrations which start from Pirathamai of Karthika Masam culminate on Soorasamharam day. Thiru Kalyanam is observed on the next day of Soorasamharam..