From the Good Friday Wikipedia page"
Good Friday is a Christian religious holiday commemorating the crucifixion of Jesus Christ and his death at Calvary. The holiday is observed during Holy Week as part of the Paschal Triduum on the Friday preceding Easter Sunday, and may coincide with the Jewish observance of Passover. It is also known as Holy Friday, Great Friday, Black Friday, or Easter Friday, though the last term properly refers to the Friday in Easter week.
Good Friday is a widely instituted legal holiday in many national governments around the world, including in most Western countries (especially among Anglican and Catholic nations) as well as in 12 U.S. states. Some countries, such as Germany, have laws prohibiting certain acts, such as dancing and horse racing, that are seen as profaning the solemn nature of the day.