The festival observed by Nanda Maharaja, Lord Krsna’s father, to celebrate Lord Krsna’s appearance.
The Nandotsav – Birth ceremony of Lord Sri Krishna Taken from Srimad Bhagavatam 10th Canto, 5th Chapter, translated by H.D.G. Srila A.C. Bhaktivedanta Swami Prabhupada.
As described in this chapter, Nanda Maharaja very gorgeously performed the birth ceremony for his newborn child. Then he went to Kamsa to pay taxes due and met his intimate friend Vasudeva.
There was great jubilation all over Vrindavana due to Krishna’s birth. Everyone was overwhelmed with joy. Therefore the King of Vraja, Maharaja Nanda, wanted to perform the birth ceremony for his child, and this he did. During this great festival, Nanda Maharaja gave in charity to all present whatever they desired. After the festival, Nanda Maharaja put the cowherd men in charge of protecting Gokula, and then he went to Mathura to pay official taxes to Kamsa. In Mathura, Nanda Maharaja met Vasudeva. Nanda Maharaja and Vasudeva were brothers, and Vasudeva praised Nanda Maharaja’s good fortune because he knew that Krishna had accepted Nanda Maharaja as His father. When Vasudeva inquired from Nanda Maharaja about the welfare of the child, Nanda Maharaja informed him all about Vrindavana, and Vasudeva was very much satisfied by this, although he expressed his grief because Devaki’s many children had been killed by Kamsa. Nanda Maharaja consoled Vasudeva by saying that everything happens according to destiny and that one who knows this is not aggrieved. Expecting many disturbances in Gokula, Vasudeva then advised Nanda Maharaja not to wait in Mathura, but to return to Vrindavana as soon as possible. Thus Nanda Maharaja took leave of Vasudeva and returned to Vrindavana with the other cowherd men on their bullock carts.