Christmas is an annual holiday that celebrates the birth of Jesus. It refers both to the day celebrating the birth, as well as to the season which that day inaugurates, which concludes with the Feast of the Epiphany. The date of the celebration is traditional, and is not considered to be his actual date of birth. Christmas festivities often combine the commemoration of Jesus' birth with various cultural customs, many of which have been influenced by earlier winter festivals. Although nominally a Christian holiday, it is also observed as a cultural holiday by many non-Christians.