In my not-so-expert opinion, it’s pretty easy to find pagan holidays that have been Christianized. If any research is done, it is obvious that the Christian religion is solely based on other religions and ideas. For example, the Christian religion is really founded on the idea that Jesus “died for our sins,” but Jesus died because the Jewish people thought that he was a threat to the imperial stability in Rome. He was put to death in a way common for thiefs and traitors of Rome: crucifixion. So it’s no surprising to learn that holidays like Christmas and Halloween were not originally Christian and were actually representative of something other than Jesus and all his so-called sacrifices.
Halloween started out as a pagan holiday, called “Samhain.” It was a festival celebrating the time of year that the ghosts could “mingle” with the living. It involved the sacrifice of animals, fruits and vegetables. But the Christian’s had made it their agenda to literally “wipe out” pagan holidays, because they were unable to convert all of the people to their religion. So they changed Samhain to Halloween. Christmas is another one. December 25th was the mid winter celebration of many people already, so the Christians just made their celebration of christmas on that day also.