[2]
Christmas Eve refers to the evening [3] or entire day preceding Christmas Day [4], a widely celebrated [5] festival commemorating the birth [6] of Jesus of Nazareth [7] that takes place on December 25.[4] [8] It is a culturally significant celebration for most of the Western world [9] and is widely observed as a full or partial holiday in anticipation of Christmas Day.
Links:
[1] http://www.ctio.noao.edu/noao/content/Eve-Christmas-Day
[2] http://upload.wikimedia.org/wikipedia/commons/thumb/a/a8/NASA-Apollo8-Dec24-Earthrise.jpg/600px-NASA-Apollo8-Dec24-Earthrise.jpg
[3] http://en.wikipedia.org/wiki/Evening
[4] http://en.wikipedia.org/wiki/Christmas
[5] http://en.wikipedia.org/wiki/Christmas_worldwide
[6] http://en.wikipedia.org/wiki/Nativity_of_Jesus
[7] http://en.wikipedia.org/wiki/Jesus
[8] http://en.wikipedia.org/wiki/Christmas_Eve#cite_note-Christmas_Eve-3
[9] http://en.wikipedia.org/wiki/Western_world