All over world Hindus celebrate Navratras with great devotion. Navratras literally means  "nine nights".  These nights are devoted to the worship of Goddess Durga. Navratras, are celebrated twice in a year.  Once in the bright two-week period of Shukla Paksha of the lunar month of Ashwani (Asuj in Kashmiri) – corresponding to September/October) from the 1st to the 9th date of the two week period. 
These days of Navratras are celebrated with great fervor especially in West Bengal where it is known as "Durga Puja". The Gujrati Hindus celebrate it with nine days of Garba dance. The second Navratras are celebrated during the first nine days of the bright two-week period of Shukla Paksha of the lunar month of Chaitra – corresponding to mid-March to mid-April. 
The timing of the celebrations correspond to the autumnal and vernal equinox which is also the time when seasons change and we harvest crops which adds to the glory of these celebrations.