Biswakarma Puja is an important festival in Eastern India and is dedicated to Vishwakarma, the divine architect of the architect of the universe according to Hindu Scriptures. Biswakarma Puja 2011 date is September 18 in some calendars in Bengal. Calendars in Orissa, North India and South India have marked it on September 17. Usually the festival is observed on September 17. But in 2011 Bhadra Sankranti takes place on the early morning of September 18 this is why date is marked on Sept 18 by some calendars.

Biswakarma puja is annually scheduled on the last day of the Bengali month of Bhadra, more specifically on Bhadra sankranti. That is when the sun transits from Singha (Leo) to Kanya (Virgo) sign.

The festival is mainly celebrated in Bengal, Orissa and Tripura. It is a holiday for the industrial belts in this part of India. Kite flying is a major activity on the day.

In Hindu Mythology, Vishwakarma is the divine architect of the universe. He is also called the divine carpenter and is mentioned in the Rig Veda and is credited with Sthapatya Veda, the science of mechanics and architecture.