Good Friday is a Christian religious holiday. Good Friday is a religious holiday observed primarily by Christians 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 proceeding 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 latter properly refers to the Friday in Easter week.
For more information about Goof Friday please refer to this link: http://en.wikipedia.org/wiki/Good_Friday