In the month of Purattasi, Saraswati Pooja festival is celebrated with great pomp and rejoicing. This is one of the most important All-India festivals. This festival is celebrated on the nine days, following the new-moon day of the month of Purattasi, (Aswina) and culminates on the ninth day, called the Mahanavami. Hence, this is referred to as Navaratri. The tenth day, called the Mahadasami, is also included in the celebrations and then it is called the Dasara (ten nights) festival.
This festival is identified also with Ram Lila, in North India. The ninth day is held to be the day of Ravana vadha – slaying of Ravana. Rama is considered to have performed the Navarathri pooja and secured victory over Ravana, The month of Purattasi is considered to be sacred to Mahavishnu also and on Saturdays of this month, people worship Him devoutly, observing austere Vratas, in all Vaishnava temples. A grand Brahmotsava is conducted for Sri Venkatesa Perumal at Tirupathi, during this month.