Akal Bodhon : The worship of Ma Durga in the month of Ashwin is called 'Akalbodhan'. It's an uncustomary time for commencement of the worship. Traditionally durga puja is performed during the spring (Basanta). Ram did "Chandi Puja" before his war with Ravana despite the time of year not being right. He invoked the blessings of Durga to kill Ravana. That's why Durga Puja is also called Akal Bodhon (untimely invocation).
Sandhi puja : (108 'Dip' lighted) It is being performed at the end moment of Ashtami and at the................... more on http://madurgapuja.com