In any culture festivals, and banquets and parades are how people past the time. Holidays are days looked forward to on a calendar. The Most High God is no different. There are a set of days set aside for the celebration of the Plan of God, the Will of God and the works of His hand.
However at some point during the 3rd century after a string of councils, the Emperor 'Constantine the Great' wanted to separate the catholic church from all things considered Jew or Jewish. I don t think he ever read the scripture, "...my kinsmen according to the flesh... are Israelites; to whom pertaineth the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises"(Romans 9:3-5).
Not to mention the fact the city is called 'new Jerusalem' the capital city in Israel since King David moved his throne there from Hebron.
Jesus Christ Our Passover
Nevertheless, it is human nature to want to celebrate God's goodness on earth.
There are however Holy Days (holidays) found in the Bible. 3 feasts (Unleavend Bread [7days long], Pentecost [1day], Tabernacles[8days long]), 2 memorials (The Passover, Blowing of trumpets), and 1 fast (The day of Atonement).
Come out of Babylon my people and no longer be partake of her sins. "Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues." (Revelation 18:4)