Vat Amavasya, also referred as Vata Savitri Amavasya Vrat, is observed by married women in North India. In 2012, the date of Vat Amavasya is May 20. The fasting and rituals is a three day affair and it begins on May 18, 2012. Main rituals include fasting on the day and worshipping the Banyan Tree. Married women observe Vat Amavasya puja for the well being of their husbands and for a prosperous and happy family life.
Vat Amavasya is based on the famous Savitri – Satyavan legend in the Mahabharat. In North India, Vat Puja is observed on the Jyeshta Amavasi day (no moon day).
Vat Savitri Vrat fasting is for three days. It begins on the Trayodashi day and ends on Amavasi – the fast is for three nights and ends on the fourth day. Prayers and pujas are dedicated to Vat Vriksha (Banyan Tree) and Savitri.
But nowadays most women only fast on the Amavasi day.
It must be noted that in some regions, Vat Savitri Vrat is also observed on the Jyeshta Purnima day (full moon day), especially in Western parts of India – Gujarat and Maharashtra and this is known as Vat Purnima.