So, why is it celebrated on March 17th? One theory is that that is the day that St. Patrick died. Since the holiday began in Ireland, it is believed that as the Irish spread out around the world, they took with them their history and celebrations. The biggest observance of all is, of course, in Ireland. With the exception of restaurants and pubs, almost all businesses close on March 17th. Being a religious holiday as well, many Irish attend mass, where March 17th is the traditional day for offering prayers for missionaries worldwide before the serious celebrating begins.
In American cities with a large Irish population, St. Patrick's Day is a very big deal. Big cities and small towns alike celebrate with parades, "wearing of the green," music and songs, Irish food and drink, and activities for kids such as crafts, coloring and games. Some communities even go so far as to dye rivers or streams green!
Brother Vincent, Happy St Patrick's Day!