Sharad Purnima (Sharat Poornima / Kojagari Purnima) is the Full Moon day in the month of Ashwin. In 2013, Sharad Purnima date is October 18.
It is celebrated as harvest as the rainy season comes to an end and agriculture will be on peak in many regions of India. Kaumudi Puja or Koumudi Utsav is also celebrated along with Kojagari Lakshmi Puja on Sharat Poornima. Moon God is also called as Kaumudi.
As per the popular Hindu belief, Lord Krishna has begun his divine Raas Lila with Radha and Gopis on the Sharat Purnima night. On Sharad Purnima day, devotees observe vigil and perform Lakshmi Puja. This day falls on Sharad ritu hence it is called as Sharad Poornima.
As per a legend of Sharad Purnima Lakshmi Puja, a King was suffering from financial problems. When his Queen performed the Kojagari Lakshmi vrata, his all problems were ruined out and he ruled his kingdom without any more problems.
Kumar Purnima in Orissa and Sharad Poonam in Gujarat:
In Orissa, Sharad Purnima is observed as Kumar Purnima. On Kumar Purnima day, people of Orissa observe Gaja Lakshmi Puja. Generally, this festival is dedicated to Lord Kumar, also known as Kartikeya, the son of Lord Shiva.
In Gujarat, Sharad Purnima is called Sharad Poonam. It is one of the big festivals of Gujarat.
Sharad Purnima 2012 date was October 29.