This festival is celebrated on the 8th day of the first half, Krishna Paksha, of the Bhaadrapad Maas. This is the day on which Lord Krishna appeared on this Earth. This day men, women and children all observe fast and many take the food only after the birth of lord Krishna - after 12 midnight after Krishna Darshan.

Hindu Temples are decorated with many flowers. leaves and many kinds of scenes related to Krishna's life are depicted. Even in houses this is done at a lower level. This is one of the main festivals of Brij Bhoomi, near Mathuraa in Uttar Pradesh where Lord Krishna was born.

Krishna Janm story is very famous. There was a king named Ugrasen in Mathuraa. He had a son named Kans, and a daughter named Devakee. Kans loved Devki very much. King Ugrasen liked Vasudev ji very much and Vasudev ji happened to be Kans' friend also. So he settled Devakee's marriage to Vasudev Jee. When Devakee was going to her in-law's house after marriage, God spoke from the Heaven, "O Kans! thou lovest this Devakee very much, but this Devakee's eighth child will kill you."

Hearing this, Kans got mad on Devakee, and he got ready to kill her, because after killing Devakee, he would be free from any fear from Devakee's children. His brother-in-law calmed him down and agreed up on that he can imprison them till their eighth child is born.

Somehow Kans got agreed. As soon as Kans got the news of the birth of the first child, he came to take it. He forcefully took it, and killed it by throwing it against the wall. Devakee became very sad at this, but could not do anything. Thus Kans killed her six children one by one.

Now he waited for her seventh child. There was another wife of Vasudev, named Rohinee. One day she had a dream that she should go to Devakee and bring her child into her own womb. So she went to the prison and did that. Thus the real seventh child of Devakee was secured with Rohinee. This child became Balraam Jee, Krishn's elder brother. Kans was surprised to know that although Devakee got pregnant but she didn't give birth to any child. He was very angry at this and scolded his gatekeepers for their carelessness.

Now was the time of the eighth child. Kans had given special instructions to his gatekeepers to let him know as soon the child is born. This time everybody saw Devakee pregnant but nobody saw her delivering the baby. 

So this day, on Krishn Janmaashtamee, when it was a black night, there were loud thunder storms and heavy rains, Lord Krishna appeared before Devakee and Vasudev. He explained everything to Vasudev Jee and asked him to do as He said to him.

Vasudev Jee took Lord Krishn to his friend Nand Jee and his wife Yashodaa Jee to Gokul. Vasudev carried Him in a Soop. All gatekeepers slept at that time, and all locks of the prison opened. And Vasudev Jee did not have any difficulty in coming out of the prison at all. But outside it was heavily raining, so Shesh Naag Jee came to rescue Lord Krishn to save Him from being wet He covered Lord Krishn under the shade of His head.

On the way there was the great Yamunaa river. Vasudev had to cross that river, but she was very deep, besides when she saw Lord Krishn coming, she wanted to touch His feet, so her waves were rising very high. Vasydev was very scared. How he will be successful in his mission if the situation remained like this. Lord Krishn understood everything, so He took out His one foot and touched the waters of Yamunaa Jee. Yamunaa Jee got calmed and gave them the way to go to Gokul.

In Gokul village Nand Jee was waiting for Vasudev Jee. As soon as Vasudev Jee arrived there, Nand Jee brought his new-born baby girl to him to take her to Mathuraa to give to Kans. Now Vasudev Jee was very hesitant, but could not help it, so he took the girl and went back to Mathuraa quickly without speaking a word.

When Vasudev Jee had entered his prison cell, all gates were locked like before and gatekeepers got up, as if nothing has happened. In the meantime the girl cried, so one of the gatekeepers rushed to the palace to inform Kans that Devakee has given birth to a child.

Kans came rushing to prison happily, because he thought that now after killing this child he will be at peace and will not be any more scared of his death through Devakee's child. He asked for the child. Devakee wept and cried but Kans did not listen to anything. He snatched the child from Devakee's arms and came to know that she was a girl, while he was expecting a son. So he got very angry, abused Devakee and as he threw the child against the wall like any other time, to kill her, the child fell from his hands and flew towards Heaven. From there she told Kans, "O Kans! why are you after me? You wouldn't get anything by killing me. You killer has already been born in Gokul." Kans heard this and got very angry and went to his palace back.