Kalratri Mata is worshipped on the 7th day of Navratri. She is considering quite an aggressive form of Maa Parvati. Her name means: ‘Kaal’ - time/death & ‘Ratri’ - night. As per her name, she is considering as the destroyer of darkness.
Goddess Kalratri has dark black complexion. She rides on a donkey. The Goddess has four hands; both right hands stay in Varada and Abhaya Mudra; and the left two hands carry sword and a hook weapon.
As the legend goes, there were two demons - Shumbha and Nishumbha, who had capture the entire Devlok (sacred abode of Devas). The King of the Gods, Indra was beaten badly. In order to get their home back, they sought help from Maa Parvati. While they were explanation the entire story to her, she was bath inside. In order to help them, she sent Chandi to help them.
When Goddess Chandi went to the devils for war, Shumbha and Nishumbha sent Chanda and Munda to fight. Hence, she shaped Maa Kalratri to kill them. After killing them, she got the name Chamunda. After that, Raktabeeja arrived. This demon had the ability of recreating his body with his blood. Every time Goddess killed him and his blood spilled on the ground, the demon made a new body for him. So, Kalratri Durga takes Decision to drink all his blood, so that nothing drops down on the floor; and it actually worked!
There are many other legends linked with Kalratri. One of them tells how Maa Parvati became Durga. As per that legend, the devil Durgasur was trying to attack Kailash (the sacred abode of Shiva-Parvati) in the absence of Maa Parvati. So, she sent Kaal Ratri for dealing with him. The guards of the devils tried to attack Kala Ratri, but she grew bigger and bigger in size. Eventually, she got too powerful to handle. Durgasur had to leave, but Maa Kalratri told him that his death is near. Another time when Durgasur tried to attack Kailash, Maa Parvati fight with him and killed him. Hence, she got the name Durga.
Planet Saturn (Shani) is ruled by the Kalratri Mata. Worship her helps in pacifying the ill impact of this planet.
ॐ देवी कालरात्र्यै नमः॥
एकवेणी जपाकर्णपूरा नग्ना खरास्थिता।
लम्बोष्ठी कर्णिकाकर्णी तैलाभ्यक्त शरीरिणी॥
वर्धन मूर्धध्वजा कृष्णा कालरात्रिर्भयङ्करी॥
या देवी सर्वभूतेषु माँ कालरात्रि रूपेण संस्थिता।
नमस्तस्यै नमस्तस्यै नमस्तस्यै नमो नमः॥
करालवन्दना घोरां मुक्तकेशी चतुर्भुजाम्।
कालरात्रिम् करालिंका दिव्याम् विद्युतमाला विभूषिताम्॥
दिव्यम् लौहवज्र खड्ग वामोघोर्ध्व कराम्बुजाम्।
अभयम् वरदाम् चैव दक्षिणोध्वाघः पार्णिकाम् मम्॥
महामेघ प्रभाम् श्यामाम् तक्षा चैव गर्दभारूढ़ा।
घोरदंश कारालास्यां पीनोन्नत पयोधराम्॥
सुख पप्रसन्न वदना स्मेरान्न सरोरूहाम्।
एवम् सचियन्तयेत् कालरात्रिम् सर्वकाम् समृध्दिदाम्॥
हीं कालरात्रि श्रीं कराली च क्लीं कल्याणी कलावती।
कालमाता कलिदर्पध्नी कमदीश कुपान्विता॥
कुमतिघ्नी कुलीनर्तिनाशिनी कुल कामिनी॥
क्लीं ह्रीं श्रीं मन्त्र्वर्णेन कालकण्टकघातिनी।
कृपामयी कृपाधारा कृपापारा कृपागमा॥
ऊँ क्लीं मे हृदयम् पातु पादौ श्रीकालरात्रि।
ललाटे सततम् पातु तुष्टग्रह निवारिणी॥
रसनाम् पातु कौमारी, भैरवी चक्षुषोर्भम।
कटौ पृष्ठे महेशानी, कर्णोशङ्करभामिनी॥
वर्जितानी तु स्थानाभि यानि च कवचेन हि।
तानि सर्वाणि मे देवीसततंपातु स्तम्भिनी॥
With this, we hope that you will make the best of Navratris seventh day. May Kalratri Maa bless you with all the goodness of life.