Christmas celebrates the birth of Jesus Christ, who Christians believe is the son of God. His birth date is unknown because there is little information about his early life. There is disagreement among scholars on when Jesus was born. Christians celebrate Jesus' birthday on December 25. Orthodox Christians celebrate Christmas Day on or near January 7.
The word 'Christmas' comes from the old English 'Cristes maesse' , or the mass of Christ. It is likely that the Christmas date of December 25 was chosen to offset the Pagan celebrations of Saturnalia and Natalis Invicti. It it also possible that the celebration of the birth of the 'true light of the world' was set at the time of the December solstice because this is when the days in the northern hemisphere begin to grow longer. Christmas holiday customs derive from various cultures, including Teutonic, Celtic, Roman, West Asian and Christian.