Aashwin Shukla Navamee - Gauree Navamee Vrat
Aashwin Shukla Navamee (9th Day of Nav Raatri days before Dashaharaa) is the day for this Vrat. Keep fast on this day and worship Devee. This Navamee is called Pisht Navamee, that is why after keeping this fast, one should eat Pishtaann.

Mahaa Navamee
If there is a Yog of Ashtamee and Mool Nakshatra and Soorya is in Kanyaa Raashi (Virgo Sign), that is called Mahaa Navamee. It destroys all sins. This day one should worship 9 Durgaa establishing them at one place or at separate places. One should keep 18-armed Mahaa Lakshmee picture or idol flanked by other Devees. They should be established in this way - Rudrachandaa, Prachandaa, Chandograa, Chandnaayikaa, Chandaa, Chandvatee, Poojyaa, Chandaroopaa, and Ati-Chandikaa. And in the center should be 18-armed Ugrachandaa Mahish Mardinee Durgaa. Their 10-letter Mantra is - "Aum Durgey Durgey Rakshasi Swaahaa".