why is christmas december 25

It's believed that the tradition of celebrating Christmas on December 25th began with the Catholic Church, which established it as the date of Jesus Christ's birth. The date was chosen because it coincided with the winter solstice and the pagan festival of Saturnalia, which celebrated the winter solstice and the rebirth of the sun. Over time, Christmas became a holiday that celebrated the birth of Jesus Christ and the coming of light and hope during the darkest time of the year.