Christmas is celebrated on the night of 24 to 25 December and 25 all day. As a Christian feast, it commemorates each year the birth of Jesus of Nazareth. Originally, there was at that time of the pagan festivities marking the winter solstice, symbol of the rebirth of the Sun. The Christian feast was positioned on the same date to replace these feasts and, symbolically, to associate the birth of Christ to the concept of increasing light.