Topic summary
Navratri

Extracted from the Wikipedia article Navaratri.
Dates of four Navratris
According to some Hindu texts, such as the Shakta and Vaishnava Puranas, Navaratri theoretically falls two or four times in a year. Of these, the Sharada Navaratri near the September equinox (the autumn equinox in September–October) is the most celebrated, and the Vasanta Navaratri near the March equinox (the spring equinox in March–April) is the next most significant to the culture of the Indian subcontinent. In all cases, Navaratri falls in the bright half (waxing phase) of the Hindu lunisolar months. The celebrations vary by region, leaving much to the creativity and preferences of the Hindus.