St. Patricks Day 

St. Patricks day is celebrated in March 17 because its a way to commemorate St. Patrick who happens to be the reason for the holiday and because its the day he died. St. Patrick was a bishop in ireland who wasn't very popular it wasn't until after  his death due to many myths. One of the myths was that he was the one that got rid of snakes that were in Ireland, even though its impossible since snakes can't live in Ireland due to the weather. In the beginning St. Patricks also happen to be a day were the christians had a feast of a sort but later in America it turn into parties and parade. As for the color green we wear it because it has a lot of representation towards Ireland the color green is for the flag and the way the entire country has green life. But the interesting fact is that we wear green because of another myth which happen to be that leprechauns don't pitch a person when wearing green, which is why everyone wears green to not get pinched by one.