Krishna Janmashtami is observed on the Ashtami tithi, the eighth day of the dark half or Krishna Paksha of the month of Bhaadra in the Hindu calendar, when the Rohini Nakshatra (called Aldebaran in the West) is ascendant. The festival always falls within mid-August to mid-September in the Gregorian calendar. In 2009, for example, the festival was celebrated on the 14th of August.