Hayagreeva (Hayagriva) Jayanti is believed to be the day when Hayagreva incarnation of Lord Vishnu appeared on earth. Hayagreeva Jayanti 2021 date is August 21. (For some communities it is on August 22). Hayagreeva is a unique incarnation of Lord Vishnu with the head of a horse and the body of a human being. The purpose of this Avatar was to retrieve the stolen Vedas from the demons.