Saint Patrick's feast day, as a kind of national day, was already being celebrated by the Irish in Europe in the ninth and tenth centuries. In later times, he became more and more widely known as the patron of Ireland.[21] Saint Patrick's feast day was finally placed on the universal liturgical calendar in the Catholic Church due to the influence of Waterford-born Franciscan scholar Luke Wadding[22] in the early 1600s. Saint Patrick's Day thus became a holy day of obligation for Roman Catholics in Ireland. It is also a feast day in the Church of Ireland. The church calendar avoids the observance of saints' feasts during certain solemnities, moving the saint's day to a time outside those periods. St Patrick's Day is occasionally affected by this requirement, when 17 March falls during Holy Week. This happened in 1940, when Saint Patrick's Day was observed on 3 April to avoid it coinciding with Palm Sunday, and again in 2008, where it was officially observed on 14 March. St Patrick's Day will not fall within Holy Week again until 2160.[23][24] However, the secular celebration is always held on 17 March.
In 1903, St Patrick's Day became an official public holiday in Ireland. This was thanks to the Bank Holiday (Ireland) Act 1903, an act of the United Kingdom Parliament introduced by Irish Member of Parliament James O'Mara.[25] O'Mara later introduced the law that required that pubs and bars be closed on 17 March after drinking got out of hand, a provision that was repealed in the 1970s. The first St Patrick's Day parade held in the Irish Free State was held in Dublin in 1931 and was reviewed by the then Minister of Defence Desmond Fitzgerald.
In the mid-1990s the government of the Republic of Ireland began a campaign to use St Patrick's Day to showcase Ireland and its culture.[26] The government set up a group called St Patrick's Festival, with the aims: