Hariyali Amavasya is observed on Amavasya Tithi in the holy month of Sawan or Sharvana. It is considered highly auspicious in North India. Hariyali Amavasya usually occurs three days before the famous Hariyali Teej.
Temples in North India, particularly in Mathura and Vrindavan, arrange special Darshan on Hariyali Amavasya day. On this day, thousands of Krishna devotees gather at Dwarkadhish temple in Mathura and Banke Bihari temple in Vrindavan to have the special Darshan of Lord Krishna.
Phool Bangla at Banke Bihari temple in Vrindavan is world famous. Other than Krishna temples, various Shiva temples also arrange special Shiva Darshan on the day of Hariyali Amavasya.
Hariyali Amavasya occurs in Shravana month. It matches with the Ashadha Amavasya in the states of Andhra Pradesh, Karnataka, Tamil Nadu, Goa, Maharashtra and Gujarat, where Amavasyant Lunar Calendar is followed.
Hariyali Amavasya is also known as Haryali Amavas and Hariyali Amas in Gujarat.