Katyayani Jayanti is the first appearance day of Goddess Katyayani Mata. In 2017, Katyayani Jayanti date is September 19.
In North Indian Hindi calendars, Ashwin Krishna Chaturdashi is observed as Katyayani Jayanti. As per Marathi, Gujarati, Telugu and Kannada calendars, it falls on Krishna Paksha Chaturdashi in Bhadrapada Month.
Katyayani was born as the daughter of Katyayana, who was performed an austere penance to get the Mother Goddess as his daughter.
Maa Katyayani was worshipped by Lord Vishnu, Shiva and Brahma and all other Gods for three days – 7th, 8th and 9th days during Shukla paksha of Ashwin month – to demolish demon Mahishasura.
Katyayani pleased with the puja of Gods and demolished Mahishasura on Vijaya Dashami day.