Devotees of Maa Durga across the world are celebrating Navratri festival, that goes on till Oct. 10 this year. Seventh day of Navratri pooja is envisaged as one of the great days in Durga Pooja and Navratri. The most violent and fearsome appearance of Goddess Durga manifests itself in the form of Kalaratri, and she is worshipped on this day. She is also glorified with name ‘Kali Maa’. 
Dugra took this form to destroy all the demons and bring order back to Earth. In Hindu mythology, she was the only Goddess who could kill the demon Raktabeej. She represents herself as the death of Kaal. Although her appearance is terrifying, her grace is generous toward devotees.  Because of her auspicious power within her ferocious form, Goddess Kalaratri is also known as Goddess Shubhankari.
Om Devi Kalaratryai Namah॥
Observe a fast on this day to please Goddess Kalaratri. This will get you enormous happiness, power and comforts in life. For tantriks, the seventh night of the Navratri is also known as the Night of Siddhis, and they perform many rituals to please the Goddess.