Navaratri is an annual Hindu festival observed in honour of the goddess Durga, an aspect of Adi Parashakti, the supreme goddess. It spans over nine nights (and ten days), first in the month of Chaitra (March/April of the Gregorian calendar), and again in the month of Ashvin (September–October). It is observed for different reasons and celebrated differently in various parts of the Hindu Indian cultural sphere. Theoretically, there are four seasonal Navaratri. However, in practice, it is the post-monsoon autumn festival called Sharada Navaratri.