Why is Sunday called Sunday?

Answer 1

Palm Sunday is in commemoration of Jesus' entry into Jerusalem in the last week before He was arrested and crucified. People lined His path or waved palm branches, a symbol at the time of victory.

John 12:12-13

On the next day much people that were come to the feast, when they heard that Jesus was coming to Jerusalem,Took branches of palm trees, and went forth to meet him, and cried, Hosanna: Blessed is the King of Israel that cometh in the name of the Lord.

AnswerJohn Shelby Spong (Jesus for the NonReligious) puts it this way: The ]ewish eight day celebration of the harvest, known as Sukkoth, and also called the Festival of the Tabernacles or Booths, was probably the most popular holiday among the Jews in the first century. In the observance of Sukkoth, worshippers processed through Jerusalem and in the Temple, waving a bunch of leafy branches made of willow, myrtle and palm. As they waved these branches in that procession, the worshippers recited words from Psalm 118, the psalm normally used at Sukkoth. Among these words were "Save us, we beseech you, O Lord." Save us in Hebrew is hosianna or 'hosanna'. This is typically followed by "Blessed is the one who comes in the name of the Lord. (Psalm 118:25-6)."

Mark's Gospel was the earliest of the New Testament gospels. It took the Sukkoth traditions and transferred them from autumn to the Passover season for the procession story. Mark 11:8 says (NAB), "Many people spread their cloaks on the road, and others spread leafy branches that they had cut from the fields." The words used at the Sukkoth are reflected in Mark 11:9: "And they that went before, and they that followed, cried, saying, Hosanna; Blessed be he that cometh in the name of the Lord." Because the Passover season is too early for 'leafy branches' (except palms), John actually says 'palm branches', creating our modern tradition of Palm Sunday.