Good Friday (from the senses pious, holy of the word “good”), 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 preceding Easter Sunday, and may coincide with the Jewish observance of Passover. It is also known as Holy Friday, Great Friday or Easter Friday, though the latter normally refers to the Friday in Easter week.
Based on the details of the Canonical gospels, the Crucifixion of Jesus was most probably on a Friday. The estimated year of Good Friday is AD 33, by two different groups, and originally as AD 34 by Isaac Newton via the differences between the Biblical and Julian calendars and the crescent of the moon. A third method, using a completely different astronomical approach based on a lunar Crucifixion darkness and eclipse model (consistent with Apostle Peter’s reference to a “moon of blood” in Acts 2:20) points to Friday, 3 April AD 33.
The Celebration of the Passion of the Lord takes place in the afternoon, ideally at three o’clock, but for pastoral reasons a later hour may be chosen. The vestments used are red (more commonly) or black (more traditionally).[ Before 1970, vestments were black except for the Communion part of the rite when violet was used. Before 1955 black was used throughout. If a bishop or abbot celebrates, he wears a plain mitre.
Good Friday is the Friday before Easter, which is calculated differently in Eastern Christianity and Western Christianity. Easter falls on the first Sunday following the Paschal Full Moon, the full moon on or after 21 March, taken to be the date of the vernal equinox. The Western calculation uses the Gregorian calendar, while the Eastern calculation uses the Julian calendar, whose 21 March now corresponds to the Gregorian calendar's 3 April.