Most Christians are familiar with the reason Good Friday is celebrated, but for those who'd like a closer look at the religious holiday celebrated on Easter weekend, here are some excerpts from Wikipedia:
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.
In the United States, Good Friday is not a government holiday at the federal level; however, individual states, counties and municipalities may observe the holiday. Good Friday is a state holiday in Connecticut, Delaware, Florida, Hawaii, Indiana, Kentucky (half day), Louisiana, New Jersey, North Carolina, North Dakota, Tennessee and Texas. State and local government offices and courts are closed, as well as some banks and postal offices in these states, and in those counties and municipalities where Good Friday is observed as a holiday. Good Friday is also a holiday in the U.S. territories of Guam, U.S. Virgin Islands and Puerto Rico.
The stock markets are closed on Good Friday but the foreign exchange and bond trading markets open for a partial business day. Most retail stores remain open, while some of them may close early. Public schools and universities are often closed on Good Friday, either as a holiday of its own, or part of spring break. The postal service operates, and banks regulated by the federal government do not close for Good Friday.
In some governmental contexts Good Friday has been referred to by a generic name, particularly "spring holiday", presumably to avoid accusations of violating the Establishment Clause of the First Amendment of the U.S. Constitution, although neither the word "good" nor "Friday" describes any particular religion.