INF017

The decision to set Jesus' birth on 25 December

The Council of Nicaea (325) established liturgical rules that enabled Dionysius Exiguus to set Jesus' birth on 25 December. This date was chosen for symbolic reasons and to replace pagan winter solstice festivals, notably Sol Invictus. Although not historically verifiable, 25 December became the official date of Christmas in the Western Church.

2 min Christmas 25 December Council of Nicaea Dionysius Exiguus Sol Invictus

The Council of Nicaea's decision to set Jesus' birth on 25 December

The in 325 influenced in several ways. Although the council established the date of Easter rather than Christmas, it set important rules for determining Christian liturgical dates. used these rules to calculate the date of Easter and, consequently, also determined the date of Jesus' birth, which he set on 25 December.

In other words, Dionysius's work was based in part on decisions and calculations established at the , allowing a degree of continuity and uniformity in how important dates in the Christian calendar were determined.

The in 325 set the date of Christmas celebrations on 25 December for symbolic reasons and to replace pagan winter solstice festivals (Sol Invictus, the ‘Unconquered Sun’). Despite this error, 25 December became the official date of Christmas celebrations in the Western Christian Church.