Christianity is an important festival to commemorate the birth of Jesus. Also known as Jesus Christmas, the Lord's Nativity day, Catholicism also known as Jesus Christmas. The date of Jesus' birth is not recorded in the Bible. In 336 ad, the Roman Church began to celebrate this festival on December 25. December 25 was the birthday of the sun god stipulated by the Roman Empire. Some people think that the reason for choosing this day to celebrate Christmas is that Christians believe that Jesus is the just and eternal sun. After the middle of the 5th century, Christmas, as an important festival, became the tradition of the church and gradually spread among the eastern and Western churches. Due to different calendars and other reasons, the specific dates and forms of activities held by various sects are also different. Christmas customs spread to Asia mainly in the middle of the 19th century. Japan and South Korea were influenced by Christmas culture. Now it has become a common custom in the west to exchange gifts, hold banquets, and add a festive atmosphere with Santa Claus and Christmas tree. Christmas has also become a public holiday in the western world and many other regions.