St. Patrick's day 

Saint Patrick was a fifth-century Romano-British Christian missionary and bishop in Ireland. Known as the "Apostle of Ireland", he is the primary patron saint of Ireland, along with saints Brigit of Kildare and Columbia. This holiday is celebrated because it was the traditional death date of Saint Patrick. On Saint Patrick's day we wear green as this was the color he was said to wear. Saint Patrick's  is celebrate through the world  especially in Ireland and in Great Britain.