From Joe Carter:
Holy Week is the week before Easter, a period which includes the religious holidays of Palm Sunday, Maundy Thursday, Good Friday, and Holy Saturday. Here's what you should know about the days that commemorate the Passion of Christ:
1. Holy Week observances likely began in Jerusalem in the earliest days of the church, though the term first appears in the writings of fourth century bishops, Athanasius, bishop of Alexandria, and Epiphanius, bishop of Constantia. Holy week does not include Easter Sunday.
2. The first recording of a Holy Week observance was made by Egeria, a Gallic woman who made a pilgrimage to the Holy Land about 381-384. In an account of her travels she wrote for a group of women back in Spain, Egeria describes the Palm Sunday she observed in Jerusalem:
. . . all the children who are [gathered at the top of the Mount of Olives], including those who are not yet able to walk because they are too young and therefore are carried on their parents' shoulders, all of them bear branches, some carrying palms, others, olive branches. And the bishop is led in the same manner as the Lord once was led.
3. Because of the difficulty in some parts of the world of procuring palms for Palm Sunday, leaves from yew, willow, olive, or other native trees are frequently used. The Sunday was often designated by the names of these trees, as Yew Sunday, or by the general term Branch Sunday.
4. An archaic and infrequently used name for the Wednesday before Easter is "Spy Wednesday", named for Judas' becoming a spy for the Sanhedrin.
5. Maundy Thursday is the day before Good Friday. The term "Maundy" is derived from the Latin word mandatum (commandment). The term refers to the commandment given by Jesus at the Last Supper: "A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another." (John 13:34)
6. The historical origins of the "Good" in Good Friday remain unclear, though some entomologists believe the term "good" is an archaic form of "holy."
7. In Catholic and Eastern Orthodox traditions, Holy Saturday commemorates the "harrowing of hell," the time between his Crucifixion and his Resurrection when Christ is believed to have descended into hell. Some Protestants, however, don't believe that Scripture warrants believing the claim, found in the Apostle's creed, that "[Christ] descended into hell." As John Piper says, "there is no textual basis for believing that Christ descended into hell."
8. In Medieval Europe, Christians would abstain from eating eggs and meat during Lent. Eggs laid during that time were often boiled to preserve them and were given as Easter gifts to children and servants. Some traditions claim the Easter egg is symbolic of the resurrection of Jesus, with the shell of the egg representing the sealed Tomb and cracking the shell representing the Resurrection. Christians in the Middle East and in Greece painted eggs bright red to symbolize the blood of Christ.
9. The Christian scholar Bede (673-735 AD, aka, the Venerable Bede) claimed in his book De Ratione Temporum that Easter was named after Eostre, a pagan goddess of the Saxon people in Northern Europe. Later scholars, however, claim that the term derives from the Anglo-Saxon word "oster", meaning "to rise" or for their term for the Spring equinox, "Eostre."