Krishna Janmashtami (Devanagari कृष्ण जन्माष्टमी kṛṣṇa janmāṣṭami), also known as Krishnashtami, Saatam Aatham, Gokulashtami, Ashtami Rohini, Srikrishna Jayanti, Sree Jayanthi or sometimes merely as Janmashtami, is a Hindu festival celebrating the birth of Krishna, an avatar of the god Vishnu.
Krishna Janmashtami is observed on the Ashtami tithi, the eighth day of the dark half or Krishna Paksha of the month of Shraavana in the Hindu calendar, when the Rohini Nakshatra is ascendant. The festival always falls within mid-August to mid-September in the Gregorian calendar. In 2010, for example, the festival was celebrated on 2 September, and in 2011 on 22 August in North India and on 21 August in South Indian states like Kerala.
(... from Wikipedia on 2012-04-17 22:15:42)