Navaratri is an annual Hindu festival observed in the honour of the goddess Durga. It spans over nine nights, first in the month of Chaitra, and again in the month of Sharada. 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. The festival is celebrated in the bright half of the Hindu calendar month Ashvin, which typically falls in the Gregorian months of September and October.