Gender masculine Gianni is a form of Greek name Ιωάννης.Feasts and saints related to given name Gianni Synaxis of Prophet Forerunner and Baptist John Feast day January 7 When is Gianni's name day? Gianni's Day is celebrated on January 7 in memory of Synaxis of Prophet Forerunner and Baptist John. Variantes et traductions Τζαννής (el) Log in or register to post comments Be the first to rate this name Leave this field blank