Purnima Upavas vrat vidhi time Importance

Purnima, or the full moon day is of extreme importance according to traditional Hindu astrology. According to a lunar calendar markd the end of a month and is an auspicious day to observe various puja and rituals.

In south India the full moon day is known as Pournami.

Importance of the Purnima –

During the full moon day or purnima, the moon shines at it’s brightest and thus eradicates all darkness and illuminating the self,
It is believed to fetch prosperity to people,
Pujas carried out during any purnima day is said to yield the maximum effect,
Fasting on the purnima days is said to have a cleansing and purifying effect on the body, mind and soul,
Many gods took birth on the purnima days, like Hanuman, Kartik etc,
Kartik Purnima is an important day, when Lord Shiva had slain the demon Tripurasurs. It is
also the day, when the first avatar of Vishnu, Matsya was born,
Satyanarayan Puja to Lord Vishnu is offered only on purnima days,
Lord Buddha too was born in the auspicious day of a purnima,
Numerous scientific research have shown that gravitational forces of the moon on the punima day is at its maximum, and has a positive effect on every individual in terms of stabilization of metabolic rate, increase in energy, reduction of acidity and a fine balance between mind and body.
Rituals related to Purnima –

The devotee must bathe before the sunrise and a fast from morning to night. Lord Shiva and Lord Vishnu must be worshipped. However one can take food once during the day, but it should be without salt and must not consume cereals or pulses. Satya Narayana  Puja may be offered.

source: 123newyear.com