Holika Dahan is observed and celebrated on the very previous night of the Holi. Holika Dahan time remains intact that is between the period just after the sunset and the purnima tithi ends before the 12:00 AM as per the Hindu scriptures.
Hence, the preparation of the Holika Dahan starts by collecting the wood and dry grass material for firing up in open space near to the temple. The burning of Holika is symbol of the victory of good over the evil.
In some places people after roasting backed grains in the fire, they used to take that back as a good luck and fortune belief. Women takes fast on the Holika Dahan day till the puja gets finished.