From Citizendium, the Citizens' Compendium
Christmas Eve is the name given to the 24th of December, the day before Christmas Day.
It is marked by preparations for Christmas Day, and particularly by religious observances.
In some European traditions, Christmas Eve traditions eclipse those of Christmas Day: the main meal is eaten and gifts opened on Christmas Eve, often following church. However, in most Christian communities, Christmas Eve is a time of preparation, and in addition to the religious practices, it is a day of last-minute shopping and gift wrapping, Christmas Tree decoration, Carol singing and food preparation.