Complex sentence: The main ritual in this temple is Sharadiya Durga Puja which starts on the night of Krishna Paksha Ashtami which falls before Mahalaya and ends on Ashwin Shukla Paksha Navami.
Split into simpler sentences: The main ritual in this temple is Sharadiya Durga Puja which starts on the night of Krishna Paksha Ashtami. This falls before Mahalaya and ends on Ashwin Shukla Paksha Navami.