St. Joseph's Day is, in Western Christianity, the principal feast of St. Joseph, the husband of the Blessed Virgin Mary.
Why is it important?
St. Joseph's Day has the rank of a solemnity in the Catholic Church. It is a feast or commemoration in the provinces of the Anglican Communion, and a feast or festival in the Lutheran Church. Saint Joseph's Day is the Patronal Feast day for Poland as well as for Canada, persons named Joseph, Josephine, etc., for religious institutes, schools and parishes bearing his name, and for carpenters. It is also Father's Day in some Catholic countries, mainly Spain, Portugal, and Italy. It is not a holy day of obligation for Catholics in the United States.