Goddess Matangi is one of the Dasa Mahavidyas. She is a
manifestation of Goddess Parvati. Matangi Jayanti is believed to be the day
when she made her appearance on earth. Matangi Jayanti 2018 date is April 18. It is observed on the Vaishakh Shukla Paksha Tritiya – third day during
the waxing phase of moon in Vaishakh month as per traditional Hindu calendar in
North India .
This form of Mother Goddess Shakti is only worshipped in
very rare temples.
Some scholars also associate Goddess with Madurai Meenakshi
who is worshipped at the famous Madurai
Temple
You can read more about Goddess Matangi in this article.