Where is St. Patrick's Day, celebrated on March 17th, observed as a major holiday?

St. Patrick's Day, observed annually on March 17th, is a cultural and religious holiday commemorating Saint Patrick, the patron saint of Ireland. He's credited with bringing Christianity to Ireland in the 5th century. The day evolved from a religious feast to a celebration of Irish culture and heritage. While the holiday is celebrated by Irish communities worldwide, it holds particular significance in Ireland itself. In both Northern Ireland and the Republic of Ireland, St. Patrick's Day is a public holiday, marked by parades, traditional music, dancing, and the wearing of green attire, especially shamrocks. The scale of the celebrations and the deep cultural connection make it a major holiday there. While you might see some St. Patrick's Day festivities in other parts of the UK like England, Scotland, and Wales, they aren't public holidays and the celebrations are not as widespread or culturally central as they are in Ireland.