March 17 is the feast day of St. Patrick, the patron saint of Ireland. Long before the time of St. Patrick, the pagan people of the Emerald Isle used the three-leaf shamrock as a charm against sorcery, witches, and fairies-a charm that was borrowed by St. Patrick to explain the concept of the Holy Trinity, the Three-In-One. Christian or pagan, the shamrock symbolizes the end of a dark winter and the promise of a brighter spring. It also promises good luck, but only if you find it accidentally!