What calendar date is Christmas Eve in Western Christianity?

In Western Christianity, Christmas Eve falls on December 24.

It is the day or evening before Christmas Day, which is observed on December 25. Christmas Eve is both a religious observance and a major cultural occasion, often marked by family gatherings, carols, gift preparation, festive meals, and church services.

The prominence of the evening has a liturgical explanation. Many Christian traditions treat the day as beginning at sunset, a practice connected with Jewish and early Christian understandings of sacred time. This helps explain why Christmas celebrations can begin on the evening of December 24 rather than waiting until the morning of December 25.

Midnight Mass and other Christmas vigils are traditionally held on this date, reflecting the belief that Jesus’ birth occurred at night. The date is not universal across all Christian traditions, however: churches using different calendars may celebrate Christmas Eve on January 6 by the Gregorian calendar. That distinction should not obscure the standard Western answer: December 24.