This day is in Baisakh (April) during third lunar day of the light fortnight. The fast is called Parshu Rama Dwadashi. This day is also auspicious because God Vishnu's sixth incarnation~ Parshu Rama was born on this day. In ancient times, this birth day of valorous, ferocious warriors and vanity personified Brahmin born Kshatrye tempered Parshu Rama, was celebrated with great pomp and show. Later on during the medieval and modern periods, this celebration was rarely arranged; but now with the reawakening of Hinduism in India, the birth day of Parshu Rama is again become an important fasting, festival, procession and satsang (congregation for religious purpose) arranged in most of the towns, particularly in Northern India.
Parshu Rama was an enemy of Kshatrye Kings because some of them (Viswamitr) had caused atrocities on his father (Jamadgin saint) and their Kama Dhenu cow. The fast on this day is auspicious for blessings to get a son. King Veersen got a glorious son Neel as a result of this fast, on the advice of saint Jamadgin. The benefit of this fast is that the devotee enjoys his stay in Brahmiok and then, on rebirth, becomes a great king (Vrah Purana).