Saint Patrick’s Day is celebrated each year on March 17th. In Ireland, Saint Patrick’s Day is both a holy day and a national holiday. Saint Patrick is the patron saint of Ireland because he brought Christianity to the Irish. The shamrock his St. Patrick's symbol.
Saint Patrick’s Day is usually celebrated with a parade. The one in Dublin, the capital of Ireland, is very famous. But the one in New York City is one of the biggest. It lasts for hours.