The dasara celebrations, on the lavish scales now maintained, date from the beginning of the 17th century, when Raja Wodeyar came to the throne of Mysore after Sri Rangaraja, as descendent of the Vijayanagar Princes. With his ascent also dates the use of the famous throne by the Maharaja, during the festival. Raja Wodeyar who became the king of Mysore at the beginning of the 17th century, celebrated the dasara festival on a royal scale, and after him, year after year the Dasarz has gained in splendor, entertainment and attractiveness.
Festivals In Indian Society (p.171)
The [next] important festival which is an All India occurrence is Nag Panchami. The name of the festival implies that it is a day which is dedicated to the worship of snakes (Nag) and the worship is to be on the fifth day (Panchami) in the bright fortnight of Sravana (August-September)Usha Sharma