What is Janmashtami:

Krishna Janmashtami, Gokulashtami, Krishnashtami is celebrated by Hindus as the birthday of Lord Krishna. According to the Hindu Calender Krishna Janmashtamii is celebrated in Bhadrapada month on Ashtami tithi which happens to be the 8th day of Krishna Paksha's dark half. It generally falls between August to September. This year it falls on 10th August, 2012.

History of Janmashtami:

Mathura was led by Kansa a wicked king. He had a sister Devaki, who was married to Vasudeva. It was predicted that Sri Krishna would be born to Devaki and would kill the wicked king Kansa. This enraged Kansa and he had all the male child of Devaki killed, after imprisoning Devaki and Vasudeva. But since the eight avatar of Lord Vishnu was bound to kill Kansa, Sri Krishna was born in midnight. All the other children born to Devaki, except Balaram were killed.

Vasudeva managed to save the child from the cruel clutches of Kansa and he exchanged child Sri Krishna with female child of Yahoda. Krishna lived in Gokul during his infancy till the age of eleven years to hide himself from the clutches of his maternal uncle, Kansa. Finally, Sri Krishna kills Kansa.

On Janmashtami Day:

On the day of Janmashtami, Temples are decorated for the occasion. People visit the temple and offer their prayers to Sri Krishna. Janmaashtami, popularly known in Mumbai and Pune as Dahi Handi, is celebrated with enormous zeal and enthusiasm.
The handi is a clay pot filled with buttermilk that is positioned at a convenient height prior to the event. The topmost person on the human pyramid tries to break the handi by hitting it with a nariyal (coconut) as being a sign of purity, truth etc. in Hinduism.
When that happens the buttermilk is spilled over the entire group, symbolizing their achievement through unity. Handis are set up around the city, and groups of youngsters, called Govinda Pathaks, travel around in trucks trying to break as many handis as possible during the day.

Celebrations Across the World:

Janmashtami is celebrated with fervor all over India and with the spread of Hinduism,it is celebrated with similar emotion all across the globe.