Srirangam of South India is said to be one of foremost temples for the Vaishnavas. Srirangam is maintained till day by "Sri Vaishnavas". "Sri Vaishnavas" celebrate the Revathi nakshatra of Panguni Month (ie., Revathi Star of March) as Birthday of Lord Ranganatha. Lord Ranganatha is a archruupa in "Swayambu" form and Lord Ranganatha is Lord Narayana himself. Since Lord Narayana dosnt have neither beginning nor end, so how come "Lord Ranganatha" have birthday at March ?