Sharad Poonam is an auspicious day when the moon is the closest to the earth in the year. Devotees celebrate by performing Rasa Dance and Singing Devotional Songs to the accompaniment of musical instruments. An offering of Dudh Pawa (rice in thick milk) is served to the Lord on this special day and Devotees enjoy the remnants (Prasada)
On this day, Lord Shree Krushna performed the divine dance (Rasa Leela) with the Gopis in Vrundavana. The discourse for this pastime can be found in Shreemad Bhagwatam - Raas Panchaadhyay Katha Canto 10 (29-33).
Lord Shree Swaminarayan also performed the Divine Rasa in Panchaala in Jina Bhais Darbaar, which Acharya Viharilalji Maharaj has described in a Kirtan He has composed.