The Feast of Saint Patrick, commonly referred to as Saint Patrick's Day, is a religious and cultural holiday celebrated annually on the 17th of March, the anniversary of the death of Saint Patrick. Observed by the various churches and the Irish community, this Christian feast day was made official in the early seventeenth century, commemorating the arrival of Christianity in Ireland. This is credited to Saint Patrick. He was later declared the country’s patron saint and national apostle. Saint Patrick’s Day has evolved into a celebration of heritage. It is displayed through public parades and festivals, and the wearing of green attire and shamrocks. The day is a public holiday in the Republic of Ireland, Northern Ireland, Newfoundland and Labrador and Montserrat, but is widely celebrated throughout the world.