In Purattasi month, Lord Venkatachalabhathy is worshiped with fasting in Saturdays as it is a favorite day for the lord in which Purattasi vratham is observed. Purattasi Masam is the sixth month in Tamil calendar. In 2012, it starts on September 16th. . People observe the fasts through out the month on Saturday . Worshipping Vishnu, Fasting on Purattasi Saturday would please the navagraha also. In Oppilappan Koil the Puratasi Festival is going on like the Bhramosthavam of Tirupathi Festival. Purattasi Saturday is the very special day to pray the god oppiliappan perumal.