Duruthu is considered as the first month of the Sinhala calendar.
The important significance of Duruthu Full Moon Poya Day, marks Gautama Buddha’s first visit to Sri Lanka.
Twenty-five centuries back, nine months after his Enlightenment, the blessed one visited Mahiyangana.
His mission was to restore peace, to create a state of freedom from war or violence.
The old chronicle Mahavamsa records and states "To free the beautiful land from the evil doing Yakkas".
On his first visit to Sri Lanka, the awakened one, arrived at a spot, where now stand the Mahiyangana stupa.
When the great teacher - the Buddha was to depart after the conversion of the Yakkas Mahiyangana area, for which purpose he had arrived, Sumana - a titular deity who posses a certain title or position but no real authority of this region, requested the Buddha to give him - Diety Sumana, a souvenir to which he could pay his offerings and homage.
Thereupon, the Gautama Buddha, the Great Master, offered Deity Sumana, some locks of his hair.
He placed it in an urn as a valuable Relic in the Mahiyangana Stupa.