The Vat Savitri/Purnima Vrat falls on the full moon day of the month of Jyeshtha, around May-June.The married Women observe Vat Savitri Vrat with the intention of preserving their husbands good fortune.On this day, women fast and worship the Vat (Bargad) tree to pray for the growth and strength of their husdand and families. All Hindu women observe this festival worshiping and propitiating Savitri as a Devi. On this day, early morning the women take bath and wear new clothes, new bangles and apply vermilion on the fore-head and the hair-parting line. Then Savitri is worshiped.
Vat Savitri Vrat Fasting is for three days and it begins on the trayodashi day and ends on Amavasi or Purnima. Some sections of Hindu society observe the vrat during Amavasi (new moon) and others during Purnima (full moon) in the Hindu month of Jyeshtha.
Vat Savitri/Purnima Vrat Legend:
The celebration derived from the story of Savitri and Satyavan. It had been foretold that Satyavan would not live for long. One day, while resting on the lap of Savitri, Satyavan suddenly passed away. The messenger of Yama, the God of death came to take Satyavan. But Savitri refused to give her beloved husband. Messenger after messenger tried to take Satyavan away, but in vain. Finally, Yama himself appeared in front of Savitri and insisted to give her husband.
Since, she was still adamant, he offered her a boon. She asked for the well being of her in-laws. He granted it to her. She then followed him as he took Satyavan's body away. He offered her another boon. She now asked for the well being of her parents. This boon, too, was granted. But she was relentless, and continued to follow him. As they approached Yama's abode, he offered her a final boon. She asked for a son. He granted it. But there was a conflict with this boon. She asked him how it would be possible for her to beget sons without her husband. Yama was stumped and realized the great devotion Savitri had for her husband. Lord Yama was impressed with her determination, and had to return the soul of her husband to his body. Henceforth, the world recognized her as the great "Sati Savitri". On the day of Vat Savitri, women hold a fast and pray for their husband's safety in the same way Savitri did.