Purnima is the period of the full moon. Vasant literally means Spring; while Purnima is full moon. As such Vasant Purnima is the full moon that comes during the Spring season.
The Purnima according to Hindu astrology has great power and qualities. Scientifically the full moon is a period when the water bodies are affected and the body too with its water balance is somewhat affected.
According to Hindu traditional beliefs, Purnima or the full moon day is an auspicious day, and Lord Vishnu in all his avatars is worshipped on the Purnima days and offered puja.
Every month has a Purnima and most of the festivities according to Hindu traditional calendar fall on the Purnima days. The Vasant Purnima is one such day of glorious festivities. Fasting is advocated on all Purnima days, and thus devotees can fast on this Vasant Purnima day too.
Some in an extreme measure fast without even consuming water too. Others partake of fruits and milk on this day and worship the deities in the evening. Rice, grain, pulses and cereals are things to be avoided during the Vasant Purnima day.
Celebrations of this auspicious day include music and dance. Large stages are erected for the performers to perform in cultural extravaganza. Festivities start a day before the Vasant Purnima. Idols from various temples are brought out for worshipping in beautifully decorated palanquins. The deities remain in the spots for the next twenty four hours. Folk dancers and performers start performing in front of the deities non- stop for the next twenty four hours. This is a unique celebration which attracts people in droves to watch the extravaganza.
In the Ganjam district of Odisha this festival of Vasant Purnima is celebrated amidst great fanfare. Ganjam incidentally has the oldest Vishnu temple in the whole district. Here too the deities are kept in palanquins for devotees to catch a glimpse. Administrative forces are deployed to keep law and order in check. Thousands congregate to witness these celebrations. It is said to be a 450 year old celebration which is being carried out till date.